EP4632110A1 - Process for the halogenation of organic compounds - Google Patents

Abstract

The present invention relates to a process for the halogenation, i.e. for the chlorination or bromination, of organic compounds V which have at least one olefinically unsaturated double bond or at least one enolizable functional group, comprising the electrolysis of a liquid reaction mixture containing the organic compound V as halogen acceptor compound, at least one halogen source containing chlorine or bromine, at least one solvent and at least one conducting salt in an undivided electrolysis cell, wherein the solvent comprises at least one organic carbonate.

Description

The present invention relates to a process for the halogenation of organic compounds which have at least one olefinically unsaturated double bond or at least one enolizable functional group by electrolysis in the presence of a halogen source containing chlorine or bromine.

The halogenation of organic compounds containing at least one olefinically unsaturated double bond or at least one enolizable functional group, i.e., a carbonyl group with an α-positioned C-H group (-C(=O)-CHR- (R = organic group)), hereinafter also referred to as compounds V, has long been known. Traditionally, this reaction is carried out by reacting compound V with elemental halogen such as chlorine or bromine. In the case of compounds V containing an olefinically unsaturated double bond, the halogen molecule adds to the olefinically unsaturated double bond to form a vicinal dihalogen compound. In the case of compounds V containing at least one enolizable functional group, the hydrogen atom of the α-positioned C-H group is substituted by halogen. Halogens such as chlorine and bromine are highly reactive, and halogenation can therefore lead to a variety of side reactions. In addition, chlorine and bromine are highly corrosive and toxic, making their handling difficult and requiring complex safety precautions. Therefore, there is a fundamental need to replace the elemental halogen in these reactions with other halogen sources.

Organohalogen compounds, i.e., organic compounds containing halogen atoms bonded to carbon atoms, such as 1,2,3,4,5,6-hexachlorocyclohexane (HCH) or 1,2,5,6,9,10-hexabromododecane (HBCD), which were used extensively in the past as flame retardants, are ecologically problematic because, if released into the atmosphere, they degrade only slowly and, moreover, accumulate in living organisms, thus entering the food chain. Their disposal is complex and usually involves incineration, requiring the use of large quantities of incendiary additives to burn the flame-resistant substances. Even then, the combustion products must be laboriously separated from the flue gas. to prevent exposure to toxic combustion products. Using HCH as an example, too low a combustion temperature leads to the formation of phosgene or even dioxins. There has therefore been no shortage of attempts to efficiently degrade these substances by other means, for example by thermal dehydrohalogenation or dehydrohalogenation using alkali or in supercritical water, by reduction in the presence of transition metals, or by oxidation under irradiation on tungsten oxides. Various electrochemical processes have also been described. The majority of the electrochemical processes described in the literature concern the degradation of HCH derivatives to benzene or mono- or dichlorinated benzenes and are concerned with groundwater treatment. Due to the low solubility of HCH in water, these reactions can only be carried out at low concentrations, which reduces the space-time yield of the reaction. Use as a halogen source is not described.

DONG ET AL. Science 2021, 371, 507 describe for the first time a transfer halogenation of olefinically unsaturated compounds as the halogen acceptor and dichloroethane, HCH, or HBCD as the halogen source by electrolysis of reaction mixtures containing the halogen acceptor and the halogen source in an undivided electrolysis cell. However, acetonitrile is used as the solvent, which is disadvantageous for the industrial implementation of this reaction because of its low boiling point, which complicates the workup of the products and the recycling of the electrochemical matrix. In addition, the HCH used in the reaction is not completely degraded to benzene, but polychlorinated benzenes are also produced. Finally, the work by DONG ET AL. does not describe an industrially relevant product. Neither the halogenation of alkenyl esters of aliphatic carboxylic acids, such as vinyl acetate or vinyl propionate, or alkenyl ethers, nor the halogenation of compounds that have at least one enolizable functional group or of alcohols is described. The preparation of dihaloalkyl esters of aliphatic carboxylic acids and dihaloalkyl ethers by halogenation of alkenyl esters or alkenyl ethers is not feasible with the solvents used by Dong et al.

CN 115852397 discloses a process for the chlorination or bromination of indole compounds, comprising the electrolysis of a liquid reaction mixture containing the indole compounds as halogen acceptor compound, an alkyl metal halide salt as halogen source, dimethyl carbonate as solvent and a phase transfer catalyst in an undivided electrolysis cell.

The present invention is based on the object of providing a process for the halogenation, i.e., for the chlorination or bromination, of organic compounds V which have at least one olefinically unsaturated double bond or at least one enolizable functional group, which avoids the disadvantages of conventional halogenation and that described by Dong. In particular, the process should enable the use of organic halogen sources containing bromine or chlorine and ensure both good yields and selectivities with respect to the desired halogenation reaction and extensive or complete dehalogenation of the organic halogen source. Furthermore, the process should not be limited to the halogenation of olefinically unsaturated compounds, but should also allow the halogenation of compounds which were previously not possible by the process described by Dong or for which this process does not produce good yields and/or only poor product selectivity.

It has been found that these and other objects are achieved by the process described here and below, wherein in particular a reaction solution is used which, in addition to the halogen source, the compound V and a conducting salt, contains at least one solvent which comprises at least one organic carbonate, in particular a cyclic organic carbonate.

Accordingly, the present invention relates to a process for the halogenation, i.e. for the chlorination or bromination, of organic compounds V which have at least one olefinically unsaturated double bond or at least one enolizable functional group, comprising the electrolysis of a liquid reaction mixture containing the organic compound V as halogen acceptor compound, at least one halogen source containing chlorine or bromine, at least one solvent and at least one conducting salt in an undivided electrolysis cell, wherein the solvent comprises at least one organic carbonate.

The process according to the invention is associated with a number of advantages. Compared to the classic halogenation with elemental chlorine or bromine, it allows the use of organic chlorine compounds or organic bromine compounds as halogen sources. Furthermore, it allows a highly selective preparation of vicinal dichloro compounds and vicinal dibromo compounds. The process also enables an efficient preparation of α-chloro and α-bromocarbonyl compounds if the compound V used has at least one enolizable functional group. In addition, the process enables the preparation of α-chloro and α-bromoacetals if The starting compound V is a vinyl ether that has a CH group in the α-position to the vinyl ether oxygen. Furthermore, the process according to the invention allows the use of electricity as a safe and cost-effective oxidizing and reducing agent, making it an inherently safe process that also generates no significant reagent waste. Furthermore, it allows the convergent use of both electrode reactions.

• Bei Einsatz von HCH als Halogenquelle ermöglicht das organische Carbonat eine vollständig selektive Reduktion von HCH zu Benzol und beim Einsatz von HBCDD die selektive Reduktion zu Cyclododecatrien. Im Unerschied zu Dong wird die Bildung von ein- oder mehrfach chlorierten Benzolen nicht oder nur in geringerem Ausmaß beobachtet.
• Der Einsatz von organischem Carbonat als Lösungsmittel erleichtert die Aufarbeitung der Produkte und ermöglicht die Rückführung des Lösungsmittelgemsichs ermöglicht.
• Der Einsatz von organischem Carbonat, insbesondere cyclischen organischem Carbonat, als Lösungsmittel führt insbesondere bei Einsatz von Verbindungen mit elektronenreichen Doppelbindungen, insbesondere bei Vinylestern organischer Carbonsäuren als Verbindung V zu einer selektiven Bildung von 1,2-Dichlorethylestern bzw. 1,2-Dibroethylestern, z. B. bei Einsatz von Vinylacetat zu 1,2-Dichlorethylacetat bzw. 1,2-Dibroethylacetat in hohen Ausbeuten und Umsatzraten, was mit der Methode von Dong et al. nicht oder nur eingeschränkt möglich war. Vergleichbare Vorteile beobachtet man auch bei anderen Verbindungen V mit elektronenreichen Doppelbindungen, z. B. bei 1-Alkenylethern, isnbesondere Vinylethern, olefinisch ungesättigten Lactonen, in denen wenigstens ein vinylisches C-Atom der olefinischen Doppelbindung an Ringsauerstoffatom des Lactons gebunden ist, sowie olefinisch ungesättigten Carbonaten, in denen wenigstens ein vinylisches C-Atom der olefinischen Doppelbindung an ein Sauerstoffatom der Carbonatgruppe gebunden ist.
• Der Einsatz von organischem Carbonat als Lösungsmittel erlaubt eine selektive Herstellung α-Chlor- und α-Bromacetalen, wenn als Ausgangsverbindung V ein Vinylether eingesetzt wird, der in der α-Position zum Vinylether-Sauerstoff eine CH-Gruppe aufweist.
• Der Einsatz von organischem Carbonat als Lösungsmittel erlaubt eine selektive Herstellung von α-Chlor- und α-Bromcarbonylverbindungen, wenn die eingesetzte Verbindung V wenigstens eine enolisierbare funktionelle Gruppe aufweist.
• Der Einsatz von organischem Carbonat als Lösungsmittel erleichtert die Durchführung der Reaktion in Flusselektrolysen sowie die Durchführung der Reaktion mit Hilfe einer bipolaren und/oder gestaffelten Elektrodenanordnung. Die erleichtert die Skalierung der Reaktionen auf industrierelevante Maßstäbe.

Compared to the known transfer halogenation, the present invention has the following advantages in particular:

• When HCH is used as the halogen source, the organic carbonate enables a fully selective reduction of HCH to benzene, and when HBCDD is used, a selective reduction to cyclododecatriene. In contrast to Dong, the formation of mono- or polychlorinated benzenes is not observed or is observed only to a lesser extent.
• The use of organic carbonate as solvent facilitates the processing of the products and enables the recycling of the solvent mixture.
• The use of organic carbonate, especially cyclic organic carbonate, as a solvent leads, particularly when using compounds with electron-rich double bonds, especially vinyl esters of organic carboxylic acids as compound V, to the selective formation of 1,2-dichloroethyl esters or 1,2-dibroethyl esters, e.g., when using vinyl acetate, to 1,2-dichloroethyl acetate or 1,2-dibroethyl acetate in high yields and conversion rates, which was not possible or only possible to a limited extent with the method of Dong et al. Similar advantages are also observed with other compounds V with electron-rich double bonds, e.g., vinyl acetate. B. in the case of 1-alkenyl ethers, in particular vinyl ethers, olefinically unsaturated lactones in which at least one vinylic C atom of the olefinic double bond is bonded to the ring oxygen atom of the lactone, and olefinically unsaturated carbonates in which at least one vinylic C atom of the olefinic double bond is bonded to an oxygen atom of the carbonate group.
• The use of organic carbonate as solvent allows a selective production of α-chloro- and α-bromoacetals if a vinyl ether is used as starting compound V, which has a CH group in the α-position to the vinyl ether oxygen.
• The use of organic carbonate as solvent allows a selective preparation of α-chloro- and α-bromocarbonyl compounds if the compound V used has at least one enolizable functional group.
• The use of organic carbonate as a solvent facilitates the reaction in flow electrolysis, as well as the reaction using a bipolar and/or staggered electrode arrangement. This facilitates the scaling of the reactions to industrially relevant scales.

Here and below, the term "olefinically unsaturated double bond" refers to a carbon-carbon double bond (= C=C double bond) that is not part of an aromatic ring system. Preferably, the double bonds are derived from ethylene, in which one or two hydrogen atoms are replaced by an organic residue.

The term "electron-rich" in relation to olefinically unsaturated double bonds refers to those olefinic double bonds in which at least one donor atom, in particular an oxygen atom, is bonded to a C atom of the olefinically unsaturated double bond.

Here and in the following, the prefix C _n -C _m indicates the number of carbon atoms that the compound or organic residue designated by it can have.

Here and in the following, "alkyl" means a linear or branched, saturated aliphatic hydrocarbon group which preferably has 1 to 10 (C ₁ -C ₁₀ alkyl) and in particular 1 to 6 C atoms, e.g. B. for methyl, ethyl, 1-propyl, 2-propyl (= isopropyl), 1-butyl, 2-butyl, 2-methyl-1-propyl, 2-methyl-2-propyl (= tert-butyl), 1-pentyl, 2-pentyl, 3-pentyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-Methyl-2-butyl, 3-Methyl-2-butyl, 1-Hexyl, 2-Hexyl, 3-Hexyl, 2-Methyl-1-pentyl, 2-Methyl-2-pentyl, 2-Methyl-3-pentyl, 3-Methyl-1-pentyl, 3-Methyl-2-pentyl, 3-Methyl-3-pentyl, 1,1-Dimethyl-1-butyl, 2,2-Dimethyl-1-butyl, 2,3-Dimethyl-1-butyl, 1-heptyl, 2-heptyl, 1-octyl, 2-octyl, 2,2-4-trimethyl-1-pentyl, 1-nonyl, 2-nonyl, 8-methyl-1-nonyl, 1-decyl or 2-decyl. The alkyl group is unsubstituted or can carry 1, 2, 3, 4, 5 or 6 substituents R ^Al which are selected from C ₁ -C ₄ -alkoxy, hydroxy-C ₁ -C ₄ -alkoxy, C ₁ -C ₄ -alkoxy-C ₁ -C ₄ -alkoxy, carboxyl, C ₁ -C ₄ -alkoxycarbonyl, C ₁ -C ₄ -alkoxy-C ₁ -C ₄ -alkoxycarbonyl, fluorine, chlorine, bromine, CN, NR ^N ₂ , where R ^N is H, C ₁ -C ₄ -alkyl, hydroxy-C ₁ -C ₄ -alkyl or C ₁ -C ₄ -alkoxy-C ₁ -C ₄ -alkyl.

Here and below, "alkenyl" refers to a linear or branched aliphatic hydrocarbon group which is mono- or polyunsaturated and which generally has 2 to 10, in particular 2 to 6 or especially 2 to 4 carbon atoms, e.g. ethenyl, 1-propenyl, 2-propenyl, 1-buten-1-yl, 2-buten-1-yl, 3-buten-1-yl, 1-buten-2-yl, 2-methyl-1-propen-1-yl, 2-methyl-2-propen-1-yl, etc. The alkenyl group is unsubstituted or can carry 1, 2, 3, 4, 5 or 6 substituents R ^Al which are selected from C ₁ -C ₄ -alkoxy, hydroxy-C ₁ -C ₄ -alkoxy, C ₁ -C ₄ -alkoxy-C ₁ -C ₄ -alkoxy, carboxyl, C ₁ -C ₄ -alkoxycarbonyl, C ₁ -C ₄ -alkoxy-C ₁ -C ₄ -alkoxycarbonyl, fluorine, chlorine, bromine, CN, NR ^N ₂ , where R ^N is H, C ₁ -C ₄ -alkyl, hydroxy-C ₁ -C ₄ -alkyl or C ₁ -C ₄ -alkoxy-C ₁ -C ₄ -alkyl stands.

Here and in the following, "alkylene" refers to a branched or unbranched, saturated, divalent aliphatic hydrocarbon group which generally has 2 to 20, in particular 3 to 10 and especially 3 to 6 carbon atoms, e.g. ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, 1-methylethane-1,2-diyl, 1,1-dimethylethane-1,2-diyl, 1-methylpropane-1,3-diyl, 1,1-dimethylpropane-1,3-diyl, 2,2-dimethylpropane-1,3-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, Dodecane-1,12-diyl, etc.

Here and in the following, "alkenylene" refers to a branched or unbranched, monosaturated, divalent aliphatic hydrocarbon group which generally has 2 to 20, in particular 3 to 10 and especially 3 to 6 carbon atoms, e.g. 1,2-ethenediyl, propene-1,3-diyl, 2-butene-1,4-diyl, 1-methylethene-1,2-diyl, 1-methyl-1-propene-1,3-diyl, 2-methyl-1-propene-1,3-diyl, 1-pentene-1,5-diyl, 2-pentene-1,5-diyl, 1-hexene-1,6-diyl, 2-hexene-1,6-diyl, 3-hexene-1,6-diyl, 1-heptene-1,7-diyl, 2-heptene-1,7-diyl, 3-heptene-1,7-diyl, etc.

Here and below, "alkoxy" refers to a branched or unbranched, saturated alkyl group as defined above, which is linked to the rest of the molecule via an oxygen atom. The term "C ₁ -C ₁₀ alkoxy" refers hereinafter to an alkyl radical as defined above, which has 1 to 10 carbon atoms. The term "C ₁ -C ₄ alkoxy" hereinafter refers to an alkyl radical as defined above, which has 1 to 4 carbon atoms, for example methoxy, ethoxy, propyloxy, isopropyloxy, n-butyloxy, 2-butyloxy, sec-butyloxy, tert-butyloxy, n-pentyloxy, 2-pentyloxy, 2-methylbutyloxy, 3-Methylbutyloxy, 1,2-Dimethylpropyloxy, 1,1-Dimethylpropyloxy, 2,2-Dimethylpropyloxy, 1-Ethylpropyloxy, n-Hexyloxy, 2-Hexyloxy, 2-Methylpentyloxy, 3-Methylpentyloxy, 4-Methylpentyloxy, 1,2-Dimethylbutyloxy, 1,3-Dimethylbutyloxy, 2,3-Dimethylbutyloxy, 1,1-Dimethylbutyloxy, 2,2-Dimethylbutyloxy, 3,3-Dimethylbutyloxy, 1,1,2-Trimethylpropyloxy, 1,2,2-Trimethylpropyloxy, 1-Ethylbutyloxy, 2-Ethylbutyloxy, 1-Ethyl-2-methylpropyloxy, n-Heptyloxy, 2-Heptyloxy, 3-Heptyloxy, 2-Ethylpentyloxy, 1-Propylbutyloxy, n-Octyloxy, 2-Ethylhexyloxy, 2-Propylheptyloxy, Nonyl, Decyloxy.

Here and below, "hydroxyalkyl" refers to an alkyl group, as defined above, bearing a hydroxyl group as a substituent. Examples are hydroxymethyl, 2-hydroxyethyl, 2-hydroxypropyl, and 3-hydroxypropyl.

Here and below, "hydroxyalkoxy" refers to an alkoxy group, as defined above, bearing a hydroxyl group as a substituent. Examples are 2-hydroxyethoxy, 2-hydroxypropoxy, and 3-hydroxypropoxy.

Here and below, "alkoxyalkyl" refers to an alkyl group, as defined above, bearing an alkoxy group, as defined above, as a substituent. Examples are methoxymethyl, ethoxymethyl, 2-methoxyethyl, and 2-ethoxyethyl.

Here and below, "alkoxyalkoxy" refers to an alkoxy group, as defined above, bearing an alkoxy group, as defined above, as a substituent. Examples are 2-methoxyethoxy and 2-ethoxyethethoxy.

Here and in the following, "C ₃ -C ₁₀ -cycloalkyl" denotes a saturated, mono-, bi-, tri- or tetracyclic hydrocarbon group which generally contains 3 to 20 carbon atoms, e.g. cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclo[2.2.1]heptyl, bicyclo[3.3.0]octyl, bicyclo[3.2.1]octyl, bicyclo[2.2.2]octyl, adamantyl etc.. C ₃ -C ₂₀ -cycloalkyl is unsubstituted, but can also contain 1 or more, e.g. B. have 1, 2, 3 or 4 substituents R ^Cyc which are selected from C ₁ -C ₄ -alkyl, C ₁ -C ₄ -alkoxy, hydroxy-C 1 -C ₄ -alkyl, hydroxy-C ₁ -C ₄ -alkoxy, C ₁ -C ₄ -alkoxy-C _{1 -C 4} -alkyl, C ₁ -C ₄ -alkoxy-C ₁ -C ₄ -alkoxy, carboxyl, C ₁ -C ₄ -alkoxycarbonyl, C ₁ -C ₄ -alkoxy-C ₁ -C ₄ -alkoxycarbonyl, fluorine, chlorine, bromine, CN, NR ^N ₂ , C ₁ -C ₄ -alkyl-NR ^N ₂ , where R ^N is H, C ₁ -C ₄ -alkyl, hydroxy-C ₁ -C ₄ -alkyl or C ₁ -C ₄ -alkoxy-C ₁ - _C4- alkyl.

Here and below, "aryl" refers to an aromatic or semi-aromatic hydrocarbon group that is mono- or polycyclic and usually has 6, 9, 10, 13, or 14 carbon atoms and is preferably phenyl, naphthyl, tetrahydronaphthyl, indenyl, indanyl, fluorenyl, anthracenyl, phenanthrenyl, or naphthacenyl, particularly preferably phenyl or naphthyl. Aryl is unsubstituted but can also contain one or more, e.g., phenyl, naphthyl, phenyl, or naphthyl groups. B. carry 1, 2, 3, 4 or 5 substituents R ^Ar , which are selected from C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy, hydroxy-C ₁ -C ₄ alkyl, hydroxy-C ₁ -C ₄ alkoxy, C ₁ -C ₄ alkoxy-C ₁ -C ₄ alkyl, C ₁ -C ₄ -Alkoxy-C ₁ -C ₄ -alkoxy, carboxyl, C ₁ -C ₄ -alkoxycarbonyl, C ₁ -C ₄ -alkoxy-C ₁ -C ₄ -alkoxycarbonyl, fluorine, chlorine, bromine, CN, NR ^N ₂ , C ₁ -C ₄ -alkyl-NR ^N ₂ , where R ^N is H, C ₁ -C ₄ -alkyl, Hydroxy-C ₁ -C ₄ alkyl or C ₁ -C ₄ alkoxy-C ₁ -C ₄ -alkyl.

Here and below, "hetaryl" refers to an aromatic or semi-aromatic heterocyclic group that is mono- or polycyclic and usually has 5 to 14 ring members which, in addition to carbon, have at least one heteroatom as a ring atom selected from N, O and S, e.g. 1 to 4 N atoms or 1 atom selected from O and S and optionally 1, 2 or 3 further N atoms, and which preferably contains the groups pyridyl, quinolinyl, acridinyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, tetrazinyl, pyrrolyl, pyrazolyl, isoxazolyl, imidazolyl, oxazolyl, thiazolyl, thienyl, furyl. Hetaryl is unsubstituted, but can also contain 1 or more, e.g. B. carry 1, 2, 3, 4 or 5 substituents R ^Ar which are selected from C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy, hydroxy-C ₁ -C ₄ alkyl, hydroxy-C ₁ -C ₄ alkoxy, C ₁ -C ₄ -alkoxy-C ₁ -C ₄ -alkyl, C ₁ -C ₄ -alkoxy-C ₁ -C ₄ -alkoxy, carboxyl, C ₁ -C ₄ -alkoxycarbonyl, C ₁ -C ₄ -alkoxy-C ₁ -C ₄ -alkoxycarbonyl, fluorine, chlorine, bromine, CN, NR ^N ₂ , C ₁ -C ₄ -Alkyl-NR ^N ₂ , where R ^N represents H, C ₁ -C ₄ alkyl, hydroxy-C ₁ -C ₄ alkyl or C ₁ -C ₄ alkoxy-C ₁ -C ₄ alkyl.

Here and below, "5- to 8-membered carbocycle" refers to a saturated or unsaturated, mono- or polycyclic hydrocarbon group containing 5 to 8 carbon atoms as ring members. The carbocycle is unsubstituted, but may also have one or more, e.g., 1, 2, 3, 4, or 5, substituents R ^Cyc , where R ^Cyc is as defined above.

Here and below, "5- to 8-membered heterocycle" refers to a saturated or unsaturated, mono- or polycyclic heterocyclic group having 5 to 8 ring atoms, wherein the ring atoms, in addition to carbon, have at least one heteroatom, which is preferably selected from nitrogen, sulfur and oxygen, e.g. pyrrolidinyl, piperidinyl, morpholinyl, thiomorpholinyl, piperazinyl, hexahydroazepinyl, etc. The heterocycle is unsubstituted, but can also have 1 or more, e.g. 1, 2, 3, 4 or 5, substituents R ^Cyc , where R ^Cyc is as defined above.

The term "aliphatic carboxylic acids" refers to linear or branched saturated carboxylic acids that preferably have 1 to 30, in particular 2 to 24, carbon atoms and are unsubstituted or carry 1, 2, 3, 4, or 5 substituents R ^Al , where R ^Al is as defined above. Examples of unsubstituted aliphatic carboxylic acids are formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, mararic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, and the like.

The term "cycloaliphatic carboxylic acids" refers to carbocyclic saturated carboxylic acids that preferably have 3 to 20, in particular 5 to 24, carbon atoms and are unsubstituted or carry 1, 2, 3, 4, or 5 substituents R ^Cyc , as defined above. Carboxylic can be monocyclic or polycyclic, e.g., bi-, tri-, or tetracyclic. Examples of unsubstituted cycloaliphatic carboxylic acids are cyclopropanecarboxylic acid, cyclobutanecarboxylic acid, cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, norbornane-1-carboxylic acid, and norbornane-2-carboxylic acid.

The term "aromatic carboxylic acids" refers to carboxylic acids that contain at least one carboxyl group bonded to an aryl or hetaryl group as defined above. In addition to the carboxyl group, the aryl radicals may also contain one or more, e.g., 1, 2, 3, 4, or 5, substituents R ^Ar . where R ^Ar is as defined above. Examples of unsubstituted aromatic carboxylic acids are benzoic acid, naphthalene-1-carboxylic acid, naphthalene-2-carboxylic acid, pyridine-2-carboxylic acid, pyridine-3-carboxylic acid, pyridine-4-carboxylic acid, furan-2-carboxylic acid, furan-3-carboxylic acid, thiophene-2-carboxylic acid, and thiophene-3-carboxylic acid.

The invention relates in particular to the following embodiments 1 to 21. Here, the following process is referred to as embodiment 1: Process for the halogenation, i.e. for the chlorination or bromination of an organic compound V which has at least one olefinically unsaturated double bond or at least one enolizable functional group, comprising the electrolysis of a liquid reaction mixture comprising the organic compound V as halogen acceptor compound, at least one halogen source which comprises chlorine or bromine, at least one solvent and at least one conducting salt in an undivided electrolysis cell, wherein the solvent comprises at least one organic carbonate.

According to a preferred embodiment 2 of the process according to the invention of embodiment 1, the organic carbonate is selected from the group of di-C ₁ -C ₄ -alkyl carbonates, e.g. diethyl carbonate, and C ₂ -C ₄ -alkylene carbonates, e.g. ethylene carbonate, which is also referred to as 2-oxo-1,3-dioxolane, and propylene carbonate, which is also referred to as 4-methyl-2-oxo-1,3-dioxolane. According to a particularly preferred embodiment 2a of the process according to the invention of embodiment 1, the organic carbonate is selected from the group of C ₂ -C ₄ -alkylene carbonates, e.g. ethylene carbonate, propylene carbonate and mixtures thereof. According to a specific embodiment 2b, the organic carbonate comprises propylene carbonate or, in particular, is propylene carbonate.

According to a preferred embodiment 3 of the process according to the invention of embodiments 1, 2, 2a and 2b, the organic carbonate, in particular the C ₂ -C ₄ alkylene carbonate and especially the propylene carbonate, makes up at least 50 wt.%, in particular at least 70 wt.% or at least 95 wt.% or 100 wt.% of the total amount of solvents in the liquid reaction mixture.

According to a further embodiment 4 of the process according to any one of embodiments 1 to 3, the liquid reaction mixture comprises at least one further solvent selected from water, C ₁ -C ₆ -alkanols, C ₁ -C ₆ -fluoroalkanols, C ₁ -C ₆ -alkylnitriles, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, N-C ₁ -C ₄ -alkylpyrrolidone, e.g. N-methylpyrrolidone, C ₁ -C ₄ -alkyl esters of C ₂ -C ₄ -alkanoic acids, C ₁ -C ₄ -alkyl esters of C ₂ -C ₄ -hydroxyalkanoic acids, C ₁ -C ₄ -chloroalkanes, dihydrolevoglucosenone and mixtures thereof.

• C₁-C₆-Alkanolen, wie Methanol, Ethanol, n-Propanol, Isopropanol, n-Butanol, Isobutanol, tert.-Butanol, Ethylenglykol, 1,2-Propandiol, 1,3-Propandiyl, 1,2-Butandiol, 1,4-Butandiol, Diethylenglykol und Triethylenglykol;
• C₁-C₆-Fluoroalkanolen, wie 1,1,2,2-Tetrafluorethanol, Pentafluorethanol, Hexafluorisopropanol und Perfluor-n-propanol;
• C₁-C₆-Alkylnitrilen, wie Acetonitril, Propionitril und Butyronitril,
• C₁-C₆-Chloralkanen, wie Trichlormethan, Dichlormethan, Isomere des Dichlorethans, des Dichlorbutans oder des Dichlorpentan etc., wobei die vorgenannten Isomere keine Isomere umfassen, in denen die beiden Chloratome an vicianle

Kohlenstoffatome gebunden sind, und deren Gemischen.Preferred further solvents of embodiment 4 are selected from

• C ₁ -C ₆ alkanols, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, ethylene glycol, 1,2-propanediol, 1,3-propanediyl, 1,2-butanediol, 1,4-butanediol, diethylene glycol and triethylene glycol;
• C ₁ -C ₆ -fluoroalkanols, such as 1,1,2,2-tetrafluoroethanol, pentafluoroethanol, hexafluoroisopropanol and perfluoro-n-propanol;
• C ₁ -C ₆ -alkylnitriles, such as acetonitrile, propionitrile and butyronitrile,
• C ₁ -C ₆ -chloroalkanes, such as trichloromethane, dichloromethane, isomers of dichloroethane, dichlorobutane or dichloropentane, etc., the above-mentioned isomers not including isomers in which the two chlorine atoms are attached to vicianle

carbon atoms are bonded, and mixtures thereof.

In this embodiment 4, the total amount of the further organic solvent preferably amounts to no more than 50 wt.%, in particular no more than 30 wt.%, based on the total amount of all solvents in the liquid reaction mixture. In particular, in embodiment 4, the total amount of further solvents is in the range of 5 to 50 wt.%, in particular in the range of 5 to 30 wt.%, based on the total amount of all solvents in the liquid reaction mixture.

According to the invention, a halogen source containing chlorine or bromine is used. In principle, mixtures of different halogen sources can be used. In these cases, the different halogen sources preferably either have the same halogen or, in the case of halogen sources with different halogens, have different reactivities. The halogen sources preferably have either bromine or chlorine as the halogen. Suitable halogen sources include elemental chlorine and elemental bromine, inorganic or organic salts with chloride or bromide as the anion, and in particular organic chlorine and bromine compounds in which the bromine or chlorine atom is bonded to a nitrogen atom or a C atom, which is preferably not part of a C=C double bond. Examples of suitable chlorine sources are _Cl2 (also in the form of chloride chains), hypochlorite, hydrogen chloride, N-chlorosuccinimide, vicinal chlorinated hydrocarbons such as hexachlorocyclohexane, polyvinyl chloride, iodobenzene dichloride, chloride salts such as sodium chloride, or conducting salts with chloride anions. Examples of suitable bromine sources are Br ₂ (also in the form of bromide chains), hypobromide, hydrogen bromide, N-bromosuccinimide, vicinal bromocarbons such as HBCD, Iodobenzene tribromide, bromide salts such as sodium bromide or conducting salts with bromide anions.

According to a preferred embodiment 5 of the process according to the invention of embodiments 1 to 4, the halogen source comprises an organic chlorine compound and/or an organic bromine compound. The organic chlorine compounds and bromine compounds generally carry at least 1, in particular at least 2, e.g., 2, 3, 4, 5, or 6 bromine or chlorine atoms per molecule. The bromine or chlorine atoms are preferably bonded to a C atom that is not part of a C=C double bond. In particular, the main source of the halogen required in the electrolysis is the organic chlorine compound or the organic bromine compound.

According to a particularly preferred embodiment 6 of the process according to the invention according to embodiment 5, the organic bromine compound has at least two vicinally bonded chlorine atoms or at least two vicinally bonded bromine atoms, i.e., the chlorine or bromine atoms are bonded to two adjacent C atoms, which are preferably not part of a C=C double bond. In particular, the halogen source of this embodiment comprises one of the following two compounds: 1,2,3,4,5,6-hexachlorocyclohexane or 1,2,5,6,9,10-hexabromocyclododecane. In particular, the halogen source is one of the following two compounds: 1,2,3,4,5,6-hexachlorocyclohexane or 1,2,5,6,9,10-hexabromocyclododecane.

• Alkenylester aliphatischer, cycloaliphatischer oder aromatischer Carbonsäuren, insbesondere deren C₂-C₄-Alkenylestern, z. B. Vinylester, Allylester und 1-Methylethenylester aliphatischer, cycloaliphatischer oder aromatischer Carbonsäuren. Hierunter bevorzugt sind die Alkenylester von gesättigten aliphatischen Carbonsäuren mit 1 bis 20 C-Atomen, insbesondere mit 1 bis 12 C-Atomen; Beispiele für die Alkenylester aliphatischer, cycloaliphatischer oder aromatischer Carbonsäuren sind Vinylacetat, Allylacetat, 1-Methylvinylacetat, Vinylpropionat, Vinylbutyrat, Vinylpentanoat, Vinylhexanoat, Vinyloctanoat, Vinyldecanoat, Vinyldodecanoat, Vinylcylohexanoat, Allylcyclohexanoat, Vinylbenzoat, Allylbenzoat, 1-Methylvinylbenzoat, Vinylnaphthenoat, Allylnaphthenoat, 1-Methylvinylnaphthenoat wobei die Benzoate und Naphthenoate am Benzolring bzw. Naphthalinring unsubstituiert sind oder 1, 2, 3, 4 oder 5 Substituenten R^Ar tragen, die wie vorstehend definiert sind;
• Alkenylether aliphatischer, cycloaliphatischer oder aromatischer Alkohole, insbesondere deren C₂-C₄-Alkenylether, z. B. Vinylether, 1-Propenylether, Allylether und 1-Methylethenylether aliphatischer, cycloaliphatischer oder aromatischer Alkohole. Hierunter bevorzugt sind die Alkenylether von aliphatischen Alkoholen mit 1 bis 20 C-Atomen, insbesondere mit 1 bis 12 C-Atomen; Beispiele für die Alkenylether aliphatischer, cycloaliphatischer oder aromatischer Alkohole sind Ethylvinylether, 2-Chlorethylvinylether, n-Propylvinylether, Isopropy-Ivinylether, n-Butylvinylether, 2-Butylvinylether, Isobutylvinylether (= 2-Methylpropyllvinylether), 2-Hydroxyethylvinylether(= Ethylenglycolvinylether bzw. Ethylenglykolmonovinylether), 1,2-Propandiolmonovinylether, 1,3-Propandiolmonovinylether, 1,4-Butandiolmonovinylether (= Tetramethylyenglykolmonovinylether), 1,5-Pentandiolmonovinylether, 2-Hydroxyethoxyvinylether (= 2-[2-(etheny-loxy)ethoxy]ethanol), Cyclohexylvinylether, Phenolvinylether und Benzylvinylether;
• Olefine, insbesondere Olefine mit 4 bis 20 C-Atomen, besonders bevorzugt Olefine mit terminaler Doppelbindung, wie 1-Hexen, 1-Hepten, 1-Octen, 1-Nonen und 1-Decen, wobei die Olefine unsubstituiert sind oder 1, 2 oder 3 Substituenten R^Al tragen, die ausgewählt sind unter C₁-C₄-Alkoxy, Hydroxy-C₁-C₄-alkoxy, C₁-C₄-Alkoxy-C₁-C₄-alkoxy, Carboxyl, C₁-C₄-Alkoxycarbonyl, C₁-C₄-Alkoxy-C₁-C₄-alkoxycarbonyl, Fluor, Chlor, Brom, CN, NR^N ₂, wobei R^N für H, C₁-C₄-Alkyl, Hydroxy-C₁-C₄-alkyl oder C₁-C₄-Alkoxy-C₁-C₄-alkyl steht;
• Konjugierte Diene, insbesondere konjugierte Diene mit 4 bis 10 C-Atomen wie Butadien, Isopren, 1,3-Pentadien und 1,3-Hexadien, wobei die konjugierten Diene unsubstituiert sind oder 1, 2 oder 3 Substituenten R^Al tragen, die wie vorstehend definiert sind;
• olefinisch ungesättigte Ketone, insbesondere solche mit 4 bis 20 C-Atomen, z. B.
  • C₂-C₁₀-Alkenyl-C₁-C₁₀-alkylketone wie Methylvinylketon, Ethylvinylketon, Butylvinylketon, Vinylisopropylketon, Pent-4-en-2-on, Hex-5-en-2-on, Hex-4-en-3-on und Hept-6-en-4-on;
  • C₂-C₁₀-Alkenyl-C₃-C₁₀-cycloalkylketone wie Vinylcyclopentylketon und Vinylcyclohexylketon;
  • C₂-C₁₀-Alkenylarylketone wie Vinylphenylketon;
  • C₅-C₁₀-Cycloalkenylketone wie Cyclopent-2-en-1-on, Cyclopent-3-en-1-on, Cyclohex-2-en-1-on, Cyclohex-3-en-1-on, Cyclohept-2-en-1-on, Cyclohept-3-en-1-on und Cyclohept-4-en-1-on;
  • olefinisch ungesättigte Carbonsäuren, z. B. Acrylsäure, Methacrylsäure, Caproleinsäure, Undecylensäure (= 10-Undecensäure), Myristoleinsäure, Palmitoleinsäure, Margaroleinsäure, Petroselinsäure, Ölsäure, Eladiinsäure, Vaccensäure, Erucasäure, Gondosäure, Gadoleinsäure und Cetoleinsäure;
  • olefinisch ungesättigte Carbonsäureester, insbesondere deren Alkylester und speziell deren C₁-C₄-Alklyester, insbesondere die Ester olefinisch ungesättigten Carbonsäureester mit 3 bis 20 C-Atomen, z. B. die C₁-C₄-Alklyester der Acrylsäure, der Methacrylsäure, der Caproleinsäure, der Undecylensäure (= 10-Undecensäure), der Myristoleinsäure, der Palmitoleinsäure, der Margaroleinsäure, der Petroselinsäure, der Ölsäure, der Eladiinsäure, der Vaccensäure, der Erucasäure, der Gondosäure, der Gadoleinsäure und der Cetoleinsäure;
  • olefinisch ungesättigte Lactone wie 3H-Furan-2-on, 4-Methyl-3H-furan-2-on, 5-Methyl-3H-furan-2-on, 2H-Furan-5-on, 2,5-Dihydropyran-6-on, 2,3-Dihydropyran-6-on, 3,4-Dihydropyran-2-on und 4,5-Dihydropyran-6-on;
  • olefinisch ungesättigte Carbonate, insbesondere 5- bis 10 gliedrige Carbonate wie 1,3-Dioxol-2-on, 4-Methyl-1,3-dioxol-2-on und 4H-1,3-Dioxin-2-on.

According to a further embodiment 7 of the process according to the invention according to any one of embodiments 1 to 6, the compound V is selected from compounds having at least one, in particular one, olefinically unsaturated double bond. These compounds typically have 4 to 40 carbon atoms, in particular 6 to 30 carbon atoms. In addition to the olefinically unsaturated double bond(s), the compounds may also have one or more, e.g., 1, 2, 3, 4, 5, or 6, in particular 1, 2, or 3, other functional groups, which are selected, for example, from hydroxyl groups, alkoxy groups, in particular C ₁ -C ₄ alkoxy groups, amino groups, nitrile groups, carboxyl groups, carboxamide groups, keto groups, ether groups, sulfonyl groups, and halogen atoms such as fluorine, chlorine, or bromine. Preferred compounds V of embodiment 7 are:

• Alkenyl esters of aliphatic, cycloaliphatic, or aromatic carboxylic acids, especially their C ₂ -C ₄ alkenyl esters, e.g., vinyl esters, allyl esters, and 1-methylethenyl esters of aliphatic, cycloaliphatic, or aromatic carboxylic acids. Preferred among these are the alkenyl esters of saturated aliphatic carboxylic acids having 1 to 20 carbon atoms, especially having 1 to 12 carbon atoms; Examples of the alkenyl esters of aliphatic, cycloaliphatic or aromatic carboxylic acids are vinyl acetate, allyl acetate, 1-methylvinyl acetate, vinyl propionate, vinyl butyrate, vinyl pentanoate, vinyl hexanoate, vinyl octanoate, vinyl decanoate, vinyl dodecanoate, vinyl cyclohexanoate, allyl cyclohexanoate, vinyl benzoate, allyl benzoate, 1-methylvinyl benzoate, vinyl naphthenoate, allyl naphthenoate, 1-methylvinyl naphthenoate, where the benzoates and naphthenoates are unsubstituted on the benzene ring or naphthalene ring or carry 1, 2, 3, 4 or 5 substituents R ^Ar which are as defined above;
• Alkenyl ethers of aliphatic, cycloaliphatic, or aromatic alcohols, especially their C ₂ -C ₄ alkenyl ethers, e.g., vinyl ethers, 1-propenyl ethers, allyl ethers, and 1-methylethenyl ethers of aliphatic, cycloaliphatic, or aromatic alcohols. Preferred among these are the alkenyl ethers of aliphatic alcohols having 1 to 20 carbon atoms, especially having 1 to 12 carbon atoms; Examples of the alkenyl ethers of aliphatic, cycloaliphatic or aromatic alcohols are ethyl vinyl ether, 2-chloroethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, 2-butyl vinyl ether, isobutyl vinyl ether (= 2-methylpropyl vinyl ether), 2-hydroxyethyl vinyl ether (= ethylene glycol vinyl ether or ethylene glycol monovinyl ether), 1,2-propanediol monovinyl ether, 1,3-propanediol monovinyl ether, 1,4-butanediol monovinyl ether (= tetramethylethylene glycol monovinyl ether), 1,5-pentanediol monovinyl ether, 2-hydroxyethoxyvinyl ether (= 2-[2-(ethenyloxy)ethoxy]ethanol), cyclohexyl vinyl ether, phenol vinyl ether and benzyl vinyl ether;
• Olefins, in particular olefins having 4 to 20 C atoms, particularly preferably olefins having a terminal double bond, such as 1-hexene, 1-heptene, 1-octene, 1-nonene and 1-decene, where the olefins are unsubstituted or carry 1, 2 or 3 substituents R ^Al selected from C ₁ -C ₄ -alkoxy, hydroxy-C ₁ -C ₄ -alkoxy, C ₁ -C ₄ -alkoxy-C ₁ -C ₄ -alkoxy, carboxyl, C ₁ -C ₄ -alkoxycarbonyl, C ₁ -C ₄ -alkoxy-C ₁ -C ₄ -alkoxycarbonyl, fluorine, chlorine, bromine, CN, NR ^N ₂ , where R ^N is H, C ₁ -C ₄ -alkyl, hydroxy-C ₁ -C ₄ -alkyl or C ₁ -C ₄ -alkoxy-C ₁ -C ₄ -alkyl;
• Conjugated dienes, in particular conjugated dienes having 4 to 10 C atoms such as butadiene, isoprene, 1,3-pentadiene and 1,3-hexadiene, wherein the conjugated dienes are unsubstituted or carry 1, 2 or 3 substituents R ^Al which are as defined above;
• olefinically unsaturated ketones, especially those with 4 to 20 C atoms, e.g.
  • C ₂ -C ₁₀ alkenyl-C ₁ -C ₁₀ alkyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, butyl vinyl ketone, vinyl isopropyl ketone, pent-4-en-2-one, hex-5-en-2-one, hex-4-en-3-one and hept-6-en-4-one;
  • C ₂ -C ₁₀ alkenyl-C ₃ -C ₁₀ cycloalkyl ketones such as vinylcyclopentyl ketone and vinylcyclohexyl ketone;
  • C ₂ -C ₁₀ alkenyl aryl ketones such as vinyl phenyl ketone;
  • C ₅ -C ₁₀ cycloalkenyl ketones such as cyclopent-2-en-1-one, cyclopent-3-en-1-one, cyclohex-2-en-1-one, cyclohex-3-en-1-one, cyclohept-2-en-1-one, cyclohept-3-en-1-one and cyclohept-4-en-1-one;
  • olefinically unsaturated carboxylic acids, e.g. acrylic acid, methacrylic acid, caproleic acid, undecylenic acid (= 10-undecenoic acid), myristoleic acid, palmitoleic acid, margaroleic acid, petroselinic acid, oleic acid, eladiic acid, vaccenic acid, erucic acid, gondoic acid, gadoleic acid and cetoleic acid;
  • olefinically unsaturated carboxylic acid esters, in particular their alkyl esters and especially their C ₁ -C ₄ alkyl esters, in particular the esters of olefinically unsaturated carboxylic acid esters having 3 to 20 C atoms, for example the C ₁ -C ₄ alkyl esters of acrylic acid, methacrylic acid, caproleic acid, undecylenic acid (= 10-undecenoic acid), myristoleic acid, palmitoleic acid, margaroleic acid, petroselinic acid, oleic acid, eladiic acid, vaccenic acid, erucic acid, gondoic acid, gadoleic acid and cetoleic acid;
  • olefinically unsaturated lactones such as 3H-furan-2-one, 4-methyl-3H-furan-2-one, 5-methyl-3H-furan-2-one, 2H-furan-5-one, 2,5-dihydropyran-6-one, 2,3-dihydropyran-6-one, 3,4-dihydropyran-2-one and 4,5-dihydropyran-6-one;
  • olefinically unsaturated carbonates, in particular 5- to 10-membered carbonates such as 1,3-dioxol-2-one, 4-methyl-1,3-dioxol-2-one and 4H-1,3-dioxin-2-one.

• 1-Alkenylester aliphatischer, cycloaliphatischer oder aromatischer Carbonsäuren, insbesondere die Vinylester und die 1-Propenylester aliphatischer, cycloaliphatischer oder aromatischer Carbonsäuren, und besonderes bevorzugt deren Vinylester, beispielsweise Vinylacetat, Vinylpropionat, Vinylbutyrat, Vinylpentanoat, Vinylhexanoat, Vinyloctanoat, Vinyldecanoat, Vinyldodecanoat, Vinylcylohexanoat, Vinylbenzoat, Vinylnaphthenoat, wobei die Benzoate und Naphthenoate am Benzolring bzw. Naphthalinring unsubstituiert sind oder 1, 2, 3, 4 oder 5 Substituenten R^Ar tragen, die wie vorstehend definiert sind;
• 1-Alkylenylether aliphatischer, cycloaliphatischer oder aromatischer Alkohole, insbesondere die Vinylether und die 1-Propenylether aliphatischer, cycloaliphatischer oder aromatischer Alkohole und besonderes bevorzugt deren Vinylether, beispielsweise Ethylvinylether, 2-Chlorethylvinylether, n-Propylvinylether, Isopropylvinylether, n-Butylvinylether, 2-Butylvinylether, Isobutylvinylether (= 2-Methylpropy-Ilvinylether), 2-Hydroxyethylvinylether(= Ethylenglycolvinylether bzw. Ethylenglykolmonovinylether), 1,2-Propandiolmonovinylether, 1,3-Propandiolmonovinylether, 1,4-Butandiolmonovinylether (= Tetramethylyenglykolmonovinylether), 1,5-Pentandiolmonovinylether, 2-Hydroxyethoxyvinylether (= 2-[2-(ethenyloxy)ethoxy]ethanol), Cyclohexylvinylether, Phenolvinylether und Benzylvinylether
• mono-olefinisch ungesättigte Lactone, worin ein viylisches C-Atom der olefinischen Doppelbindung an das Ringsaurerstoffatom des Lactons gebunden ist, z. B. 3H-Furan-2-on, 4-Methyl-3H-furan-2-on, 5-Methyl-3H-furan-2-o und 3,4-Dihydropyran-2-on, und
• olefinisch ungesättigte Carbonate, worin wenigstens ein vinylisches C-Atom der olefinischen Doppelbindung an ein Sauerstoffatom der Carbonatgruppe gebunden ist, beispielsweise 1,3-Dioxol-2-on, 4-Methyl-1,3-dioxol-2-on und 4H-1,3-Dioxin-2-on.

According to a further preferred embodiment 7a of embodiment 7 of the process according to the invention, the liquid reaction mixture contains as compound V a compound which has an electron-rich olefinic double bond, in particular an olefinic double bond which is bonded to an oxygen atom, ie an olefinic double bond in which at least one of the two vinylic C atoms of the double bond is bonded to an oxygen atom. In such compounds V, the advantages of the carbonate solvent are particularly evident. Compounds V which have an electron-rich olefinic double bond include, in particular,

• 1-Alkenyl esters of aliphatic, cycloaliphatic or aromatic carboxylic acids, in particular the vinyl esters and the 1-propenyl esters of aliphatic, cycloaliphatic or aromatic carboxylic acids, and particularly preferably their vinyl esters, for example vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pentanoate, vinyl hexanoate, vinyl octanoate, vinyl decanoate, vinyl dodecanoate, vinyl cyclohexanoate, vinyl benzoate, vinyl naphthenoate, where the benzoates and naphthenoates are unsubstituted on the benzene ring or naphthalene ring or carry 1, 2, 3, 4 or 5 substituents R ^Ar which are as defined above;
• 1-Alkylenyl ethers of aliphatic, cycloaliphatic or aromatic alcohols, in particular the vinyl ethers and the 1-propenyl ethers of aliphatic, cycloaliphatic or aromatic alcohols and particularly preferably their vinyl ethers, for example ethyl vinyl ether, 2-chloroethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, 2-butyl vinyl ether, isobutyl vinyl ether (= 2-methylpropyl vinyl ether), 2-hydroxyethyl vinyl ether (= ethylene glycol vinyl ether or ethylene glycol monovinyl ether), 1,2-propanediol monovinyl ether, 1,3-propanediol monovinyl ether, 1,4-Butanediol monovinyl ether (= tetramethylyen glycol monovinyl ether), 1,5-pentanediol monovinyl ether, 2-hydroxyethoxyvinyl ether (= 2-[2-(ethenyloxy)ethoxy]ethanol), cyclohexyl vinyl ether, phenol vinyl ether and benzyl vinyl ether
• mono-olefinically unsaturated lactones in which a vinyl carbon atom of the olefinic double bond is bonded to the ring oxygen atom of the lactone, e.g. 3H-furan-2-one, 4-methyl-3H-furan-2-one, 5-methyl-3H-furan-2-o and 3,4-dihydropyran-2-one, and
• olefinically unsaturated carbonates in which at least one vinylic C atom of the olefinic double bond is bonded to an oxygen atom of the carbonate group, for example 1,3-dioxol-2-one, 4-methyl-1,3-dioxol-2-one and 4H-1,3-dioxin-2-one.

According to embodiment 7b of embodiment 7 of the process according to the invention, the liquid reaction mixture contains, as compound V, a 1-alkenyl ether, e.g., a vinyl ether or a 1-propenyl ether, of an aliphatic, cycloaliphatic, or aromatic alcohol in combination with an aliphatic or cycloaliphatic alkanol. The main reaction product obtained is not the expected 1,2-dichloro- or 1,2-dibromoalkyl ether compound, but rather an acetal of a 2-chloro- or 2-bromoaldehyde according to the following reaction equation (1):

• Alkyl, das unsubstituiert ist oder mit 1, 2, 3, 4, oder 5 Gruppen R^Al substituiert ist und das vorzugsweise 1 bis 20 C-Atome aufweist,
• Cycloalkyl, z. B. Cyclopropyl, Cyclobutyl, Cylcopentyl oder Cyclohexyl, das unsubstituiert ist oder mit 1, 2, 3, 4, oder 5 Gruppen R^Cyc substituiert ist und das vorzugsweise 3 bis 20 C-Atome aufweist,
• Aryl, z. B. Phenyl oder Naphthyl, wobei Aryl unsubstituiert ist oder mit 1, 2, 3, 4, oder 5 Gruppen R^Ar substituiert ist und das vorzugsweise 6 bis 18 C-Atome aufweist, und
• Hetaryl, z. B. Furyl, Thienyl, Pyrazolyl, Pyrrolyl, Imidazolyl, Oxazolyl, Isoxazolyl, Thiazolyl, Isothiazolyl, Pyridyl oder Pyrimidinyl, Chinolinyl, Isochinolinyl, Benzofuryl, Benzothienyl, wobei Hetaryl unsubstituiert ist oder mit 1, 2, 3, 4, oder 5 Gruppen R^Ar substituiert ist und das vorzugsweise 3 bis 20 C-Atome aufweist;
  • die Gruppe CH=C(R^b1R^b2) für die vom 1-Alkenylrest abgeleitete Gruppe steht, wobei R^b1 und R^b2 insbesondere ausgewählt sind unter H, CH₃, C₂H₅, CH₂C₂H₅, wobei der Alkenylrest vorzugsweise insgesamt 2 bis 6 C-Atome und insbesondere 2 bis 4 C-Atome aufweist;
  • R^c für die vom aliphatischen oder cycloaliphatischen Alkohol R^c-OH abgeleitete organische Gruppe, wobei R^c insbesondere ausgewählt ist unter
• Alkyl, das unsubstituiert ist oder mit 1, 2, 3, 4, oder 5 Gruppen R^Al substituiert ist und das vorzugsweise 1 bis 20 C-Atome aufweist, oder
• Cycloalkyl, z. B. Cyclopropyl, Cyclobutyl, Cylcopentyl oder Cyclohexyl, das unsubstituiert ist oder mit 1, 2, 3, 4, oder 5 Gruppen R^Cyc substituiert ist und das vorzugsweise 3 bis 20 C-Atome aufweist.

Here, R ^a represents the organic group derived from the aliphatic, cycloaliphatic or aromatic alcohol of the alkenyl ether, where R ^a is in particular selected from

• Alkyl which is unsubstituted or substituted by 1, 2, 3, 4, or 5 groups R ^Al and which preferably has 1 to 20 C atoms,
• Cycloalkyl, e.g. cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl, which is unsubstituted or substituted by 1, 2, 3, 4 or 5 groups R ^Cyc and which preferably has 3 to 20 C atoms,
• Aryl, e.g. phenyl or naphthyl, where aryl is unsubstituted or substituted by 1, 2, 3, 4, or 5 groups R ^Ar and which preferably has 6 to 18 C atoms, and
• Hetaryl, e.g. furyl, thienyl, pyrazolyl, pyrrolyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, pyridyl or pyrimidinyl, quinolinyl, isoquinolinyl, benzofuryl, benzothienyl, where hetaryl is unsubstituted or substituted by 1, 2, 3, 4, or 5 groups R ^Ar and which preferably has 3 to 20 C atoms;
  • the group CH=C(R ^b1 R ^b2 ) represents the group derived from the 1-alkenyl radical, where R ^b1 and R ^b2 are in particular selected from H, CH ₃ , C ₂ H ₅ , CH ₂ C ₂ H ₅ , where the alkenyl radical preferably has a total of 2 to 6 C atoms and in particular 2 to 4 C atoms;
  • R ^c represents the organic group derived from the aliphatic or cycloaliphatic alcohol R ^c -OH, where R ^c is in particular selected from
• Alkyl which is unsubstituted or substituted by 1, 2, 3, 4, or 5 groups R ^Al and which preferably has 1 to 20 C atoms, or
• Cycloalkyl, e.g. cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl, which is unsubstituted or substituted by 1, 2, 3, 4 or 5 groups R ^Cyc and which preferably has 3 to 20 C atoms.

Examples of suitable 1-alkenyl ethers which can be used in the process according to embodiment 7b are methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, 2-butyl vinyl ether, isobutyl vinyl ether, 2-chloroethyl vinyl ether, cyclohexyl vinyl ether, benzyl vinyl ether and phenol vinyl ether.

Examples of suitable alcohols R ^c -OH are C ₁ -C ₆ -alkanols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, 1-pentanol, 2-pentanol, 1-hexanol and C ₃ -C ₆ -cycloalkanols such as cyclopropanol, cyclobutanol, cyclopentanol or cyclohexanol.

According to a further preferred embodiment 7c of embodiment 7 of the process according to the invention, the liquid reaction mixture contains a 1-alkenyl ether, e.g., a vinyl ether or a 1-propenyl ether of an aliphatic dialcohol, as compound V. The main reaction product obtained is not the expected 1,2-dichloro- or 1,2-dibromoalkyl ether compound, but rather a cyclic acetal of a 2-chloro- or 2-bromoaldehyde, which corresponds to the main product described in equation (1), with the difference that the radicals R ^a and R ^c are linked to one another by a covalent bond.

Preferred 1-alkenyl ethers used in the process according to embodiment 7c can be described by the following formula:

HO-Alk-O-CH=C(R ^b1 R ^b2 )

wherein Alk represents a linear alkylene group having preferably 2 to 10 C atoms, in which 1, 2 or 3 non-adjacent CH ₂ groups may be replaced by O.

Examples of 1-alkenyl ethers which can be used in the process according to embodiment 7c are 2-hydroxyethyl vinyl ether (= ethylene glycol vinyl ether or ethylene glycol monovinyl ether), 1,2-propanediol monovinyl ether, 1,3-propanediol monovinyl ether, 1,4-butanediol monovinyl ether (= tetramethylethylene glycol monovinyl ether), 1,5-pentanediol monovinyl ether and 2-hydroxyethoxyvinyl ether (= 2-[2-(ethenyloxy)ethoxy]ethanol).

• aliphatische, alicyclische und aliphatisch-aromatische Ketone, z. B.
  • Di-C₁-C₁₀-alkylketone wie Aceton, Methylethylketon, Diethylketon, Hexan-2-on, Hexan-3-on, Heptan-2-on, Heptan-3-on, Heptan-4-on, Octan-2-on, Octan-3-on, Octan-4-on und dergleichen;
  • C₁-C₁₀-Alkyl-C₃-C₁₀-cycloalkylketone wie Methylcyclopentylketon, Ethylcyclopentylketon, Methylcyclohexylketon und Ethylcyclohexylketon;
  • C₁-C₁₀-Alkylarylketone wie Acetophenon, Ethylphenylketon, 1-Acetylnaphthalin, 2-Acetylnaphthalin, wobei die vorstehenden Ketone am Benzolring bzw. Naphthalinring unsubstituiert sind oder 1, 2, 3, 4 oder 5 Substituenten R^Ar tragen, die wie vorstehend definiert sind;
  • Cyloalkanone mit vorzugsweise 5 bis 12 C-Atomen, wie Cyclopentanon, 2-Methyl-cyclopentan-1-on, Cyclohexanon, 2-Methyl-cyclohexan-1-on, Cycloheptanon, Cyclooctanon, Cyclodecanon, Cyclododecanon, Norbornan-2-on und Campher (1,7,7-Trimethyl[2.2.1]bicycloheptan-2-on);
  • Aliphatische und alicyclische Aldehyde mit vorzugsweise 2 bis 12 C-Atomen, z. B. Propionaldehyd, Butyraldehyd, n-Pentanal, n-Hexanal, n-Heptanal, n-Octanal, Cyclopentancarbaldehyd, Cyclohexancarbaldehyd und Cyclooctancarbaldehyd;
  • aliphatische und cycloaliphatische 1,3-Diketone mit vorzugsweise 5 bis 12 C-Atomen, z. B. Pentan-2,4-dion, Hexan-2,4-dion, Heptan-2,4-dion, Heptan-3,5-dion, Octan-2,4-dion, Octan-3,5-dion, 2-Acetylcyclopentan-1-on, 2-Acetylcyclohexan-1-on, 2-Acetylcycloheptan-1-on, Cycohexan-1,3-dion, Cycloheptan-1,3-dion; sowie
  • aliphatische und cycloaliphatische 3-Ketocarbonsäureester, insbesondere die C₁-C-₄ Alkylester von 3-Ketocarbonsäuren mit vorzugsweise 4 bis 12 C-Atomen, z. B. die Methylester und Ethylester der 3-Oxobutansäre, der 3-Oxopentansäre, der 3-Oxohexansäre, der 3-Oxoheptansäre, der 3-Oxooctansäre, der 2-Oxocyclopentancarbonsäure und der 2-Oxocyclohexancarbonsäure.

According to a further embodiment 8 of the process according to any one of embodiments 1 to 6, the compound V is selected from compounds which have at least one, in particular one, enolizable group. As already explained, enolizable groups are carbonyl groups which carry a CH group in the α-position to the carbonyl group and accordingly exhibit keto-enol tautomerism. These compounds typically have 4 to 40 C atoms, in particular 6 to 30 C atoms. In addition to the enolizable group, the compounds can also have one or more, e.g., 1, 2, 3, 4, 5 or 6, in particular 1, 2 or 3, other functional groups which are selected, for example, from hydroxyl groups, alkoxy groups, in particular C ₁ -C ₄ alkoxy groups, amino groups, nitrile groups, carboxyl groups, carboxamide groups, ether groups, sulfonyl groups and halogen atoms such as fluorine, chlorine or bromine. Preferred compounds V of embodiment 8 are:

• aliphatic, alicyclic and aliphatic-aromatic ketones, e.g.
  • Di-C ₁ -C ₁₀ alkyl ketones such as acetone, methyl ethyl ketone, diethyl ketone, hexan-2-one, hexan-3-one, heptan-2-one, heptan-3-one, heptan-4-one, octan-2-one, octan-3-one, octan-4-one and the like;
  • C ₁ -C ₁₀ alkyl-C ₃ -C ₁₀ cycloalkyl ketones such as methyl cyclopentyl ketone, ethyl cyclopentyl ketone, methyl cyclohexyl ketone and ethyl cyclohexyl ketone;
  • C ₁ -C ₁₀ alkylarylketones such as acetophenone, ethylphenyl ketone, 1-acetylnaphthalene, 2-acetylnaphthalene, wherein the above ketones are unsubstituted on the benzene ring or naphthalene ring or carry 1, 2, 3, 4 or 5 substituents R ^Ar which are as defined above;
  • Cycloalkanones having preferably 5 to 12 C atoms, such as cyclopentanone, 2-methyl-cyclopentan-1-one, cyclohexanone, 2-methyl-cyclohexan-1-one, cycloheptanone, cyclooctanone, cyclodecanone, cyclododecanone, norbornan-2-one and camphor (1,7,7-trimethyl[2.2.1]bicycloheptan-2-one);
  • Aliphatic and alicyclic aldehydes having preferably 2 to 12 C atoms, e.g. propionaldehyde, butyraldehyde, n-pentanal, n-hexanal, n-heptanal, n-octanal, cyclopentanecarbaldehyde, cyclohexanecarbaldehyde and cyclooctanecarbaldehyde;
  • aliphatic and cycloaliphatic 1,3-diketones having preferably 5 to 12 C atoms, e.g., pentane-2,4-dione, hexane-2,4-dione, heptane-2,4-dione, heptane-3,5-dione, octane-2,4-dione, octane-3,5-dione, 2-acetylcyclopentan-1-one, 2-acetylcyclohexan-1-one, 2-acetylcycloheptan-1-one, cyclohexane-1,3-dione, cycloheptane-1,3-dione; and
  • aliphatic and cycloaliphatic 3-ketocarboxylic acid esters, in particular the C ₁ -C ₄ alkyl esters of 3-ketocarboxylic acids having preferably 4 to 12 C atoms, for example the methyl esters and ethyl esters of 3-oxobutanoic acid, 3-oxopentanic acid, 3-oxohexanoic acid, 3-oxoheptanic acid, 3-oxooctanoic acid, 2-oxocyclopentanecarboxylic acid and 2-oxocyclohexanecarboxylic acid.

According to a further embodiment 9 of the process according to any one of embodiments 1 to 8, a reaction mixture is used in which the concentration of compound V in the liquid reaction mixture is in the range from 5 to 100 g/L and in particular in the range from 5 to 50 g/L, in each case based on the total volume of the reaction mixture before the start of the electrolysis.

According to a further embodiment 10 of the process according to any one of embodiments 1 to 9, a reaction mixture is used in which the concentration of the halogen source in the liquid reaction mixture is in the range from 5 to 300 g/L and in particular in the range from 10 to 260 g/L, in each case based on the total volume of the reaction mixture before the start of the electrolysis.

According to the invention, the electrolysis solution used contains at least one conducting salt. Suitable conducting salts are, in principle, all inorganic and organic salts that are sufficiently soluble in the reaction mixture and inert under the electrolysis conditions. Suitable conducting salts are well known to those skilled in the art of electrolysis. Conducting salts containing an organic cation are preferred.

According to a preferred embodiment 11 of the process according to any one of embodiments 1 to 10, the supporting salt is selected from quaternary ammonium salts, pyridinium salts, imidazolium salts, quaternary phosphonium salts, and mixtures thereof. Particularly preferred supporting salts are tetra(C ₁ -C ₆ -alkyl)ammonium salts, tri(C ₂ -C ₆ -alkyl)methylammonium salts, and tri(C ₂ -C ₆ -alkyl)benzylammonium salts. Examples thereof are tetramethylammonium salts, tetraethylammonium salts, tetra-n-butylammonium salts, triethylmethylammonium salts, trimethylbenzylammonium salts, and triethylbenzylammonium salts. Pyridinium salts are also particularly suitable. and imidazolium salts, especially those bearing 1 or 2 C ₁ -C ₈ alkyl groups as substituents.

Suitable counterions for the aforementioned salts are, in principle, all anions that are inert under electrolysis conditions. These are well known to those skilled in the art of electrolysis.

According to a preferred embodiment 12 of the process according to any one of embodiments 1 to 10 and in particular according to embodiment 11, the anions of the conducting salt are selected from chloride, bromide, tetrafluoroborate, trifluoromethanesulfonate, tosylate, sulfate, C ₁ -C ₄ alkyl sulfate, perchlorate, acetate, hexafluorophosphate, bis(trifluoromethylsulfonyl)imide, nitrate, carbonate and bromate and in particular from chloride and bromide.

According to a preferred embodiment 13 of the process according to any one of embodiments 1 to 10 and in particular according to embodiments 11 and 12, the conducting salt is used in an amount such that its concentration in the reaction mixture is in the range from 0.01 to 0.2 mol/L and in particular in the range from 0.02 to 0.2 mol/L.

According to a preferred embodiment 14 of the process according to any one of embodiments 1 to 13, the liquid reaction mixture contains a mediator. Mediators are understood to be compounds that enable indirect electrochemical oxidation. These are compounds that can exist in different oxidation states. The mediator is electrochemically converted to the higher oxidation state, then acts as an oxidizing agent, and subsequently regenerates by electrochemical oxidation. This is therefore an indirect electrochemical oxidation of the organic compound, since the mediator is the oxidizing agent. The oxidation of the organic compound with the mediator in the oxidized form can be carried out in the electrolysis cell in which the mediator was converted to the oxidized form, or in one or more separate reactors ("ex-cell process").

According to a preferred embodiment 15 of the process according to embodiment 14, the reaction mixture contains as mediator at least one transition metal salt selected from the transition metals of groups 5-10, in particular those of the fourth period, of the Periodic Table of the Elements, according to IUPAC.

According to a preferred embodiment 16 of the method according to embodiment 15, the mediators used in the method according to the invention are Salts of manganese, copper, cobalt, nickel, chromium, vanadium, iron, ruthenium, rhodium or palladium are used.

According to a preferred embodiment 17 of the process according to embodiment 16, transition metal salts selected from Mn(II) salts, Cu(I) salts, Cu(II) salts, Co(II) salts, Ni(II) salts, Cr(II) salts, Cr(III) salts, V(III) salts, Fe(II) salts, Fe(III) salts, Ru(III) salts, Rh(III) salts, Ir(III) salts, Pd(II) salts and combinations thereof are used as mediators in the process according to the invention.

The anions of the transition metal salts are of minor importance. According to a preferred embodiment 18 of the process according to embodiments 15 to 17, the anions of the transition metal salts are selected from chloride, bromide, tetrafluoroborate, trifluoromethanesulfonate, tosylate, sulfate, C ₁ -C ₄ alkyl sulfate, e.g., methyl sulfate or ethyl sulfate, perchlorate, acetate, hexafluorophosphate, bis(trifluoromethylsulfonyl)imide, nitrate, carbonate, or bromate. Preferred transition metal salts are the bromides and chlorides of the aforementioned transition metals.

According to a preferred embodiment 19 of the process according to embodiments 15 to 18, the mediator is used in an amount such that its concentration is up to 20 mol%, based on the amount of halogen source used, and in particular in the range from 0.1 to 20 mol%, based on the amount of halogen source used.

According to the invention, the electrolysis is carried out in an undivided electrolysis cell. In contrast to a divided electrolysis cell, an undivided electrolysis cell is an electrolysis cell in which the anode compartment is not separated from the cathode compartment, so that the electrolyte in the electrolysis cell has essentially the same composition, apart from transport-related concentration differences in the region of the electrodes.

The electrolysis cell naturally has at least one anode and at least one cathode.

According to a preferred embodiment 20 of the method according to embodiments 1 to 19, the anode material of the electrolysis cell is selected from graphite, including isostatic graphite, graphite foils, graphite fibers and metal-doped graphite, glassy carbon (GC), platinum, boron-doped diamond (BDD) and mixed metal oxides comprising at least one Metal oxide from the group consisting of ruthenium oxide, iridium oxide, and tantalum oxide, preferably in combination with a titanium carrier. A particularly preferred electrode material for the anode is graphite, especially isostatic graphite.

In principle, any electrode material can be used as the electrode material for the cathode. According to a preferred embodiment 21 of the process according to embodiments 1 to 20, the cathode material of the electrolysis cell is selected from graphite, including isostatic graphite, graphite foils, graphite fibers, and metal-doped graphite, glassy carbon, platinum, boron-doped diamond, platinum, molybdenum, vanadium, tungsten, niobium, lead (which can be used either in elemental form or in the form of lead bronzes such as CuSn7Pb15), tantalum, nickel, silver, titanium, and zirconium.

Particularly preferred combinations of electrode materials are summarized in the following table anode cathode Graphite, isostatic Graphite, isostatic Graphite, isostatic Boron-doped diamond Boron-doped diamond Boron-doped diamond glassy carbon glassy carbon glassy carbon graphite RuO _x / Ti ¹⁾ graphite Graphite, isostatic Graphite fibers Graphite foil graphite Graphite, isostatic Graphite foil Graphite foil Graphite foil Graphite, isostatic Silver Graphite, isostatic CuSn7Pb15 Graphite, isostatic molybdenum Graphite, isostatic niobium Graphite, isostatic nickel Graphite, isostatic Lead Graphite, isostatic Tantal Graphite, isostatic titanium Graphite, isostatic Vanadium Graphite, isostatic tungsten Graphite, isostatic zirconium 1) Ruthenium oxide on titanium support

In principle, any electrode shape known to those skilled in the art can be used as the anode. This can consist entirely of the respective electrode material or be a carrier electrode comprising an electrically conductive carrier coated with the electrode material. Electrodes made of the respective electrode material are preferred. The electrodes used as the anode can be, for example, electrodes in the form of expanded metal, mesh, or sheet metal.

Any undivided electrolysis cells known to those skilled in the art can be used for the electrolysis, such as undivided pot cells, undivided flow cells, capillary gap cells, stacked-plate cells or staggered pot cells, and bipolar pot cells, i.e., cells with a bipolar electrode arrangement. Particular preference is given to undivided flow cells, e.g., a flow cell with forced electrolyte flow, i.e., the electrolyte is continuously passed past the electrodes, whereby the electrolyte flow can be configured as a circulation or continuous flow. Staggered pot cells, preferably with mixing, are also preferred. Staggered pot cells can also be configured as flow cells.

The arrangement of the anode and cathode in the electrolysis cell is not limited and includes, for example, arrangements of planar grids and/or plates, which can also be arranged in the form of several alternatingly polarized stacks, and cylindrical arrangements of cylindrically shaped meshes, grids, or tubes, which can also be arranged in the form of several alternatingly polarized cylinders. Bipolar-connected electrode arrangements can also be used.

Various electrode geometries are known to those skilled in the art to achieve optimal space-time yields. Suitable examples include parallel arrangements of electrode sheets, bipolar arrangements of multiple electrodes, an arrangement in which a rod-shaped anode is surrounded by a cylindrical cathode, or an arrangement in which both the cathode and the anode consist of a wire mesh, which are placed on top of each other and rolled into a cylindrical shape. The electrode spacing is typically in the range of 1 to 10 mm, and in flow cells, in the range of 0.25 to 10 mm.

The process can be carried out successfully both batchwise and continuously. The process according to the invention can also be carried out on an industrial scale. Appropriate electrolysis cells are known to those skilled in the art. All embodiments of this invention relate to both laboratory and industrial scales.

In a preferred embodiment of the invention, the contents of the electrolysis cell are thoroughly mixed. Any mechanical stirrer known to those skilled in the art can be used for this mixing of the cell contents.

By applying the electrolysis voltage to the anodes and cathodes, an electric current is passed through the electrolyte. To avoid side reactions such as overoxidation, a current density of 500 mA/cm ² , in particular 100 mA/cm ² , is generally not exceeded. The current densities at which the process is carried out are generally 1 to 500 mA/cm ² , preferably 1 to 100 mA/cm ² . The process according to the invention is particularly preferably carried out at current densities between 1 and 50 mA/cm ² .

The total duration of electrolysis naturally depends on the electrolysis cell, the electrodes used, and the current density. The optimal duration can be determined by a specialist through routine experiments, e.g., by taking samples during electrolysis.

Typically, the amount of current required to achieve quantitative conversion is in the range of 2 to 12 F (Faraday or Coulomb/mol).

To prevent deposits on the electrodes, the polarity can be reversed at short intervals. The polarity reversal can occur at intervals of 30 seconds to 10 minutes, but preferably at intervals of 30 seconds to 2 minutes. For this purpose, it is advisable for the anode and cathode to be made of the same material.

According to the process according to the invention, the electrolysis is generally carried out at a temperature in a range from 0 to 100 °C, preferably 10 to 90 °C, in particular 15 to 90 °C.

In the process according to the invention, the electrolysis is generally carried out at a pressure below 2000 kPa, preferably below 1000 kPa, in particular below 150 kPa, e.g., in the range from 50 to 1000 kPa, in particular 80 to 150 kPa. It is particularly preferred to carry out the process according to the invention at a pressure in the range of atmospheric pressure (101 ± 20 kPa).

The halogenation product obtained by the process according to the invention can be recovered from electrolytes by conventional methods known to those skilled in the art. For example, the halogenation product formed during electrolysis can be removed or depleted from the electrolyte by distillation or extraction.

Distillation processes known to the person skilled in the art are suitable as distillation methods, such as vacuum distillation, distillation under a protective gas atmosphere, rotary evaporators, Kugelrohr distillation and the use of various columns such as Vigreux, packed and rotating band columns.

For extraction, the electrolyte can be mixed with an organic solvent that is immiscible or only partially miscible with the carbonate solvent used, for example, to separate the resulting halogenation product (liquid-liquid extraction). Suitable organic solvents include hydrocarbons with 5 to 12 carbon atoms, such as pentane, hexane, cyclohexane, heptane, or octane.

The resulting halogenation product can also be removed from the electrolyte by solid-phase extraction. For this purpose, a solid-phase extraction agent is added to the electrolyte. The halogenation product adsorbed onto the extraction agent can then be eluted from the solid phase using organic solvents known to those skilled in the art. This yields a concentrated crude product, which can then be more easily purified and isolated by distillation.

The following examples serve to illustrate the invention.

I.1 Materials and equipment

Analytical grade chemicals were purchased and used from common suppliers such as Carl Roth TCI, Sigma Aldrich, and Acros.

Unless otherwise stated, the hexachlorocyclohexane used is a stereoisomer mixture of 1,2,3,4,5,6-hexachlorocyclohexane.

Unless otherwise stated, the hexabromocyclododecane used is a stereoisomer mixture of 1,2,5,6,9,10-hexabromocyclododecane.

The electrode materials used were isostatic graphite, glassy carbon (SIGRADUR ^® G, from HTW Hochtemperatur Werkstoffe GmbH, Thierhaupten, Germany), graphite foil (Sigraflex foil), boron-doped diamond (BDD), lead, copper-tin-lead (CuSn7Pb15), molybdenum, nickel, niobium, silver, tantalum, titanium, vanadium, tungsten, zirconium, and ruthenium oxide DSA.

The electrolysis cells used were from IKA. 5 mL glass vials were used for the batch experiments and Teflon cells for the flow experiments.

The galvanostat used is an HMP4040 from Rohde & Schwarz (Rohde & Schwarz GmbH & Co. KG, Munich, Germany).

• Injektortemperatur: 250 °C;
• Programm: Methode "Medium": 50 °C Starttemperatur für 1 min, Heizrate: 17.5 °C·min^-1 bis 300 °C, 300 °C Endtemperatur für 4.72 min.

Gas chromatography was performed on a Shimadzu GC-2010 (Shimadzu, Japan) using an HP-5MS column (Agilent, USA; length: 30 m, inner diameter: 0.25 mm, film thickness: 0.25 µm, carrier gas: helium (pressure: 26.7 kPa, total flow rate: 22.8 mL◆min ^-1 , column flow: 0.68 mL◆min ^-1 , linear velocity: 30.0 cm◆sec ^-1 , purge flow: 5.0 mL◆min ^-1 , split ratio: 25.0)).

• Injector temperature: 250 °C;
• Program: Method "Medium": 50 °C starting temperature for 1 min, heating rate: 17.5 °C min ^-1 to 300 °C, 300 °C final temperature for 4.72 min.

Gas chromatography-coupled mass spectrometry was performed using a Shimadzu GCMS-QP2010 SE single quadrupole (Shimadzu, Japan) (mass range: m/z 1.5 to 1000, measurable FWHM: 0.5 to 2.0 u; EI scan S/N: 1 pg octafluoronaphthalene m/z 272 S/N ≥ 600 (helium gas); high-speed scan rate: 10000 u/sec).

I.2 General working procedure (AAV1) for batch reactions in 5 mL glass vials

For the batch reactions, 5 mL glass vials from the ^IKA® Screening System (IKA-Werke GmbH & Co. KG, Staufen, Germany) were used. These vials were heated during the reactions in a commercially available stainless steel block. The dimensions of the electrodes were 7 cm x 1 cm x 0.3 cm, and those of the isostatic graphite electrodes were 5 cm x 1 cm x 0.3 cm. The glass vials were sealed with a Teflon lid with precisely fitting holes for the electrodes.

For the reactions, 145.4 mg of hexachlorocyclohexane (HCH) (0.5 mmol) with 0.5 mmol of conducting salt were dissolved in 5 mL of the solvent used in a 5 mL glass vial. Then, 1.5 mmol (3.0 eq.) of the acceptor substrate, such as 297.5 mg of methyl 10-undecenoate (MUD), was added. The cell was sealed with the lid, which specified an electrode distance of 1 cm. The electrode thus protruded 3.5 cm into the reaction solution. The experiments were carried out galvanostatically at a current density of 4 mA cm ^-2 and 50 °C. 9 F (434.2 Q) based on the HCH were applied in each case, and after the reaction, 70 µL of mesitylene was added as a GC standard.

Scale-up reactions were carried out in pot cells with a volume of 50 mL and 500 mL, and in stacked cells with a volume of 0.8 L and 1.5 L, respectively.

The dimensions of the electrodes were 10 cm x 2.3 cm x 0.3 cm for cells with a volume of 50 mL and 22.5 cm x 5.7 cm x 0.3 cm for cells with a volume of 500 mL. The electrode spacing was 5 mm in each case. The electrodes were preferably graphite electrodes.

The stacked cells preferably had isostatic graphite electrodes, which were alternately connected as cathode and anode. The electrode spacing was 5 mm. The dimensions of the electrodes were 16 cm x 6.4 cm x 0.3 cm (10x) in cells with a volume of 0.8 L and 21 cm x 8 cm x 0.3 cm (12x) in cells with a volume of 1.5 L.

I.3 General working procedure (AAV2) for flow reactions in different cell types

Temperature-controlled flow cells from the ^IKA® Screening System (IKA-Werke GmbH & Co. KG, Staufen, Germany) were used for the flow reactions. An IPC-N ISM936 peristaltic pump from Ismatec was used to control the flow rate. The electrode dimensions were 12 cm x 4 cm x 0.3 cm for the temperature-controlled cell with a 1 mm spacer.

For the reactions, analogous concentrations were chosen as in AAV1, only the volume of the mixtures was increased. The experiments were carried out galvanostatically at a current density of 4 to 20 mA cm ^-2 and 50 - 75°C. In each case, 9 - 15 F relative to the HCH were applied, and after the reaction, 70 µL of mesitylene was added as a GC standard. Furthermore, flow rates of 0.5 to 10 mL min ^-1 were selected.

II. Production of vicinally dihalogenated products in batch processes Example 1.1: Methyl 10,11-dichloroundecanoate

According to the modified AAV1, hexachlorocyclohexane (145.5 mg, 0.5 mmol, 1.0 eq.) was reacted with methyl 10-undecenoate (362.9 mg, 1.83 mmol, 3.7 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (82.8 mg, 0.5 mmol) and manganese(II) chloride (5.0 mg, 0.025 mmol) were also added to the solution, and the solution was electrolyzed galvanostatically at 75 °C under room atmosphere and at 10 °F. Isostatic graphite electrodes (5 cm x 1 cm x 0.3 cm) were preferably used as the anode and cathode. After extracting the product with 3 x 5 mL of n-pentane, the pentane phases were combined, dried over magnesium sulfate, filtered, and the pentane was removed under reduced pressure. The product was obtained as a colorless, highly viscous liquid in a yield of 37% (0.174 g, 0.68 mmol) and detected by GC-MS.
m/z: 268 (100.0%), 270 (65.1%), 269 (13.3%), 272 (11.0%), 271 (8.6%), 273 (1.4%)

Examples 1.2 to 1.24: Preparation of methyl 10,11-dichloroundecanoate using different electrodes

For the reactions carried out according to AAV1, the electrodes listed in Table 1 were used. Propylene carbonate was used as the solvent, and tetraethylammonium chloride (82.8 mg, 0.5 mmol) and manganese(II) chloride (5.0 mg, 0.025 mmol) were additionally added to the reaction solution. The conversions and yields determined using GC calibration curves are also listed in Table 1. Table 1: Example anode cathode HCH sales/% Benzene yield/% MUD sales/% Cl ₂ MUD ³⁾ -Yield/ % 1.2 graphite graphite 72 21 >99 45 1.3 graphite BDD ¹⁾ 86 0 99 37 1.4 BDD ¹⁾ graphite 55 4 68 13 1.5 BDD ¹⁾ BDD ¹⁾ 65 0 76 22 1.6 GC2 ⁾ GC2 ⁾ 61 0 66 27 1.7 GC2 ⁾ graphite 92 0 >99 25 1.8 RuO _x / Ti graphite 90 0 >99 40 1.9 graphite Graphite fibers 92 33 99 32 1.10 Graphite foil graphite 79 60 >99 44 1.11 graphite Graphite foil 68 41 94 38 1.12 Graphite foil Graphite foil 63 38 89 34 1.13 graphite Aq 72 6 96 39 1.14 graphite CuSn7Pb15 86 0 97 34 1.15 1.16 graphite Mon >99 0 >99 27 graphite Nb 86 0 99 46 1.17 graphite Ni 74 0 >99 39 1.18 graphite Pb 76 8 99 42 1.19 graphite Ta 90 0 >99 31 1.20 graphite Ti 90 0 99 37 1.21 graphite V 94 0 >99 27 1.22 graphite W 88 0 98 36 1.23 graphite Zr 82 32 99 42 ¹⁾ BDD: Boron doped diamond
²⁾ GC: glassy carbon
³⁾ Cl ₂ MUD: Methyl 10,11-dichloroundecanoate

Examples 1.25 to 1.37: Preparation of methyl 10,11-dichloroundecanoate using different conducting salts

For the reactions carried out according to AAV1, the supporting electrolyte listed in Table 2 was used. Propylene carbonate was used as the solvent, graphite electrodes were used as the cathode and anode, and manganese(II) chloride (5.0 mg, 0.025 mmol) was added to the reaction solution. The conversions and yields determined using GC calibration curves are also listed in Table 2. Table 2: Example Conductive salt HCH sales/% Benzene yield/% MUD sales/% Cl ₂ MUD yield/% 1.25 Tetramethylammonium chloride >99 71 98 87 1.26 Tetraethylammonium chloride 94 96 99 56 1.27 Tetrabutylammonium chloride >99 92 >99 41 1.28 Tetrabutylammonium chloride ▪ Hydrate >99 94 >99 44 1.29 Tetramethylammonium tetrafluoroborate 13 13 89 3 1.30 Tetraethylammonium tetrafluoroborate 79 64 90 69 1.31 Tetrabutylammonium tetrafluoroborate 90 95 97 94 1.32 Triethylmethylammonium chloride 91 98 >99 38 1.33 Benzyl trimethyl ammonium chloride >99 83 >99 61 1.34 Benzyl triethylammonium chloride >99 159 >99 70 1.35 Tetrabutylammonium acetate >99 63 >99 78 1.36 Tetraethylammonium triflate 93 86 95 79 1.37 [Ethyl-methyl-immidazoline][chloride] 51 51 99 28

Examples 1.38 to 1.50: Preparation of methyl 10,11-dichloroundecanoate using different catalysts

For the reactions carried out according to AAV1, the catalyst listed in Table 3 was used in an amount of 0.025 mmol. Propylene carbonate was used as the solvent, graphite electrodes were used as the cathode and anode, and tetraethylammonium chloride (82.8 mg, 0.5 mmol) was added to the reaction solution. The conversions and yields determined using GC calibration curves are also listed in Table 3. <u>Table 3:</u> Example catalyst HCH sales/% Benzene yield/% MUD sales/% Cl ₂ MUD yield/% 1.38 Manganese(II) chloride tetrahydrate 100 75 >99 67 1.39 Manganese(II) acetate tetrahydrate 93 77 >99 62 1.40 Manganese(II) triflate 100 70 >99 64 1.41 Copper(II) chloride 92 70 >99 66 1.42 Copper(II) acetate hydrate 100 71 >99 70 1.43 Cobalt(II) chloride 100 83 >99 65 1.44 Cobalt(II) acetate tetrahydrate 100 73 >99 56 1.45 Nickel(II) chloride hexahydrate 83 69 >99 57 1.46 Nickel(II) acetate tetrahydrate 100 75 >99 62 1.47 Chromium(II) chloride 88 70 >99 59 1.48 Chromium(III) chloride 91 70 >99 61 1.49 Vanadium(III) chloride 84 72 >99 58 1.50 Iron(II) chloride tetrahydrate 81 66 >99 23

Example 2: 1,2-Dichlorododecane

According to the modified AAV1, hexachlorocyclohexane (145.5 mg, 0.5 mmol, 1.0 eq.) was dissolved with 1-dodecene (311.3 mg, 1.83 mmol, 3.7 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (82.8 mg, 0.5 mmol) and manganese(II) chloride (5.0 mg, 0.025 mmol) were also added to the solution, and the solution was electrolyzed galvanostatically at 75 °C under room atmosphere and with the application of 10 °F. Isostatic graphite electrodes (5 cm x 1 cm x 0.3 cm) were preferably used as the anode and cathode. After extraction of the product with 3 x 5 mL of n-pentane, the pentane phases were combined, dried over magnesium sulfate, filtered, and the pentane removed under reduced pressure. The product was obtained as a colorless, highly viscous liquid in a yield of 16% (0.073 g, 0.29 mmol). The product was detected by GC-MS.
m/z: 238 (100.0%), 240 (64.7%), 239 (13.3%), 242 (10.7%), 241 (8.5%), 243 (1.4%)

Example 3: 1,2-Dichloroethyl acetate (= 1,2-dichloroethyl acetate)

• m/z: 156.0 (100.0%), 158.0 (64.4%), 160.0 (10.5%), 157.0 (4.5%), 159.0 (2.9%)
• ¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 6.49 (dd, J = 7.3, 4.5 Hz, 1H), 3.87-3.83 (m, 2H), 2.18 (s, 3H)

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with vinyl acetate (258 mg, 275 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) and manganese(II) chloride (30.0 mg, 0.15 mmol) were also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and with the application of 7.2 F at a current density of 5 mA cm ^-2 . Isostatic graphite electrodes (5 cm x 1 cm x 0.3 cm) were preferably used as the anode and cathode. Separation was carried out by fractional distillation over magnesium sulfate under reduced pressure. The product was isolated as a colorless liquid in the second fraction. (Yield: 87%, 409.8 mg, 2.61 mmol). Benzene was isolated in the first fraction without detecting any chlorinated benzenes. This reaction was also carried out on a scale 10-fold and 100-fold larger. Additionally, this product was prepared according to AAV2 in a flow cell using a 50 mL batch at a volume flow of 1 mL min ^-1 and an electrode spacing of 1 mm. The product was detected by GC-MS.

• m/z: 156.0 (100.0%), 158.0 (64.4%), 160.0 (10.5%), 157.0 (4.5%), 159.0 (2.9%)
• ¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 6.49 (dd, J = 7.3, 4.5 Hz, 1H), 3.87-3.83 (m, 2H), 2.18 (s, 3H)

Example 4: 1,2-Dichloroethylpropionate (= Propionic acid (1,2-dichloroethyl ester)

• m/z: 170 (100.0%), 172 (64.5%), 174 (10.6%), 171 (5.6%), 173 (3.6%)
• ¹H-NMR (400 MHz, CD₂Cl₂) δ [ppm] = 6.52 (dd, J = 6.7, 4.8 Hz, 1H), 3.89-3.87 (m, 2H), 2.47-2.41 (m, 2H), 1.16 (t, J = 7.5 Hz, 3H).

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with vinyl propionate (253 mg, 275 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) and manganese(II) chloride tetrahydrate (30.0 mg, 0.15 mmol) were also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and with the application of 7.2 F at a current density of 5 mA cm ^-2 . Isostatic graphite electrodes (10 cm x 2.4 cm x 0.3 cm) were preferably used as the anode and cathode. Separation was carried out by fractional distillation under reduced pressure. The product was isolated as a colorless liquid. (Yield: 21%, 1.08 g, 6.32 mmol). The product was detected by GC-MS.

• m/z: 170 (100.0%), 172 (64.5%), 174 (10.6%), 171 (5.6%), 173 (3.6%)
• ¹ H-NMR (400 MHz, CD ₂ Cl ₂ ) δ [ppm] = 6.52 (dd, J = 6.7, 4.8 Hz, 1H), 3.89-3.87 (m, 2H), 2.47-2.41 (m, 2H), 1.16 (t, J = 7.5 Hz, 3H).

Example 5: 1,2-Dichloroethyl butyrate (= Butanoic acid (1,2-dichloroethyl ester)

• m/z: 184 (100.0%), 186 (64.5%), 188 (10.6%), 185 (6.7%), 187 (4.3%)
• ¹H-NMR (400 MHz, CD₂Cl₂) δ [ppm] = 6.52 (dd, J = 6.7, 4.8 Hz, 1H), 3.89 - 3.87 (m, 2H), 2.39 (d, J = 7.3 Hz, 2H), 1.71 - 1.65 (m, 2H), 0.96 (d, J = 7.5 Hz, 3H).

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with vinyl butyrate (288 mg, 310 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) and manganese(II) chloride tetrahydrate (30.0 mg, 0.15 mmol) were also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and with the application of 7.2 F at a current density of 5 mA cm ^-2 . Isostatic graphite electrodes (5 cm x 1 cm x 0.3 cm) were preferably used as the anode and cathode. The product was detected by GC-MS.

• m/z: 184 (100.0%), 186 (64.5%), 188 (10.6%), 185 (6.7%), 187 (4.3%)
• ¹ H-NMR (400 MHz, CD ₂ Cl ₂ ) δ [ppm] = 6.52 (dd, J = 6.7, 4.8 Hz, 1H), 3.89 - 3.87 (m, 2H), 2.39 (d, J = 7.3 Hz, 2H), 1.71 - 1.65 (m, 2H), 0.96 (d, J = 7.5 Hz, 3H).

Example 6: 1,2-dichloroisopropyl acetate

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with isopropenyl acetate (300 mg, 323 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) and manganese(II) chloride tetrahydrate (30.0 mg, 0.15 mmol) were also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and with the application of 7.2 F at a current density of 5 mA cm ^-2 . Isostatic graphite electrodes (5 cm x 1 cm x 0.3 cm) were preferably used as the anode and cathode. The product was detected by GC-MS.
m/z: 170.0 (100.0%), 172.0 (64.5%), 174.0 (10.6%), 171.0 (5.6%), 173.0 (3.6%)

Example 7: Dichloroethylene carbonate

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with vinylene carbonate (258 mg, 190 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) and manganese(II) chloride tetrahydrate (30.0 mg, 0.15 mmol) were also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and with the application of 7.2 F at a current density of 5 mA cm ^-2 . Isostatic graphite electrodes (5 cm x 1 cm x 0.3 cm) were preferably used as the anode and cathode. The product was detected by GC-MS.
m/z: 155.9 (100.0%), 157.9 (64.6%), 159.9 (10.6%), 156.9 (3.4%), 158.9 (2.2%)

Example 8: 1,2-Dibromoethyl acetate (1,2-dibromoethyl acetate)

According to the modified AAV1, hexabromocyclododecane (641.7 mg, 1.0 mmol, 1.0 eq.) was dissolved with vinyl acetate (258 mg, 275 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) and manganese(II) bromide (21.4 mg, 0.075 mmol) were added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and with the application of 7.2 F at a current density of 5 mA cm ^-2 . As anode and cathode, Isostatic graphite electrodes (5 cm x 1 cm x 0.3 cm) were used. The product was detected by GC-MS.
m/z: 245.87 (100.0%), 243.87 (51.4%), 247.87 (48.6%), 246.87 (4.3%), 244.88 (2.3%), 248.87 (2.1%)

Example 9: Benzoic acid (1,2-dichloroethyl ester)

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with vinyl benzoate (288 mg, 420 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) and manganese(II) chloride tetrahydrate (30.0 mg, 0.15 mmol) were also added to the solution. The solution was galvanostatically electrolyzed at 25 °C under room atmosphere and with the application of 7.2 F at a current density of 5 mA cm ^-2 . Isostatic graphite electrodes (5 cm x 1 cm x 0.3 cm) were preferably used as the anode and cathode. To determine the yield, the product was quantified by GC using external calibration (yield: 45%, 298 mg, 1.36 mmol).

¹ H-NMR (400 MHz, CD ₂ Cl ₂ ) δ [ppm] = 8.09 (dd, J = 8.6, 1.3 Hz, 2H), 7.69-7.63 (m, 1H), 7.54-7.49 (m, 2H), 4.10-3.99 (m, 2H).

III. Production of α-chloroketones in a batch process Example 10: 2-Chlorocyclohexanone

According to the modified AAV1, hexachlorocyclohexane (145.5 mg, 0.5 mmol, 1.0 eq.) was dissolved with cyclohexanone (258 mg, 190 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (82.9 mg, 0.5 mmol) and copper(II) chloride dihydrate (17.0 mg, 0.1 mmol) were added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 9.0 F at a current density of 5.0 mA cm ^-2 . Isostatic graphite electrodes were used as the anode and cathode. The product was detected by GC-MS.
m/z: 132.0 (100.0%), 134.0 (32.4%), 133.0 (6.6%), 135.0 (2.1%)

Example 10a: 2-Chlorocyclohexanone

• m/z: 132.0 (100.0%), 134.0 (32.4%), 133.0 (6.6%), 135.0 (2.1%)
• ¹H-NMR (400 MHz, CD₂Cl₂) δ [ppm] = 4.40 (ddd, J = 9.5, 5.3, 1.3 Hz, 1H), 2.72-2.66 (m, 1H), 2.43-2.30 (m, 2H), 2.04-1.92 (m, 3H), 1.81-1.69 (m, 2H).

According to the modified AAV1, hexachlorocyclohexane (145.5 mg, 0.5 mmol, 1.0 eq.) was dissolved with cyclohexanone (141 mg, 155 µL, 1.5 mmol, 1.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (82.9 mg, 0.5 mmol) and copper(II) chloride dihydrate (17.0 mg, 0.1 mmol) were also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 9.0 F at a current density of 5.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS. The product was then isolated from the electrolyte by distillation under reduced pressure. To determine the yield, the product was quantified by GC using external calibration (yield: 71%, 135 mg, 1.02 mmol).

• m/z: 132.0 (100.0%), 134.0 (32.4%), 133.0 (6.6%), 135.0 (2.1%)
• ¹ H-NMR (400 MHz, CD ₂ Cl ₂ ) δ [ppm] = 4.40 (ddd, J = 9.5, 5.3, 1.3 Hz, 1H), 2.72-2.66 (m, 1H), 2.43-2.30 (m, 2H), 2.04-1.92 (m, 3H), 1.81-1.69 (m, 2H).

Example 11: 2,2-Dichloro-1,3-cyclohexanedione

According to the modified AAV1, hexachlorocyclohexane (145.5 mg, 0.5 mmol, 1.0 eq.) was dissolved with 1,3-cyclohexanedione (210 mg, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (82.9 mg, 0.5 mmol) and copper(II) chloride dihydrate (17.0 mg, 0.1 mmol) were also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 6.0 F at a current density of 5.0 mA cm-2. Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS.
m/z: 179.97 (100.0%), 181.97 (63.9%), 183.97 (10.2%), 180.98 (6.6%), 182.97 (4.1%)

Example 12: 2-Oxo-cyclohexanecarboxylic acid ethyl ester

According to the following modified AAV1, hexachlorocyclohexane (145.5 mg, 0.5 mmol, 1.0 eq.) was dissolved with ethyl 2-oxocyclohexanecarboxylate (255 mg, 241 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (82.9 mg, 0.5 mmol) and copper(II) chloride dihydrate (17.0 mg, 0.1 mmol) were also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at a current density of 5.0 mA cm ^-2 , applying 6.0 F. Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS.
m/z: 204.1 (100.0%), 206.1 (33.0%), 205.1 (10.0%), 207.1 (3.3%)

Example 13: 1-Chloro-3,3-dimethylbutanone

According to the modified AAV1, hexachlorocyclohexane (145.5 mg, 0.5 mmol, 1.0 eq.) was dissolved with 3,3-dimethyl-2-butanone (300 mg, 275 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (82.9 mg, 0.5 mmol) and copper(II) chloride dihydrate (17.0 mg, 0.1 mmol) were also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at a current density of 6.0 F. ^Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS.
m/z: 134.0 (100.0%), 136.0 (32.0%), 135.1 (6.7%), 137.1 (2.1%)

Example 13a: 1-Chloro-3,3-dimethylbutanone

• m/z: 134.0 (100.0%), 136.0 (32.0%), 135.1 (6.7%), 137.1 (2.1%)
• ¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 4.37 (s, 3H), 1.21 (s, 9H).

According to the modified AAV1, hexachlorocyclohexane (2.908 g, 10 mmol, 1.0 eq.) was dissolved with 3,3-dimethyl-2-butanone (3.004 g, 3.75 mL, 30.0 mmol, 3.0 eq.) in 50 mL of propylene carbonate. Tetraethylammonium chloride (0.41 g, 2.5 mmol) and manganese(II) chloride tetrahydrate (0.30 g, 1.5 mmol) were also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 9.0 F at a current density of 5.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS. The product was then isolated from the electrolyte by distillation under reduced pressure (yield: 30%, 1.22 g, 9.06 mmol).

• m/z: 134.0 (100.0%), 136.0 (32.0%), 135.1 (6.7%), 137.1 (2.1%)
• ¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.37 (s, 3H), 1.21 (s, 9H).

Example 14: 2-Chlorophenylethanone

According to the modified AAV1, hexachlorocyclohexane (145.5 mg, 0.5 mmol, 1.0 eq.) was dissolved with 1-phenylethanone (464 mg, 450 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (82.9 mg, 0.5 mmol) and copper(II) chloride dihydrate (17.0 mg, 0.1 mmol) were also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at a current density of 5.0 mA cm ^-2 , applying 6.0 F. Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS.
m/z: 154.0 (100.0%), 156.0 (32.5%), 155.0 (8.8%), 157.0 (2.8%)

Example 14a: 2-Chlorophenylethanone

• m/z: 154.0 (100.0%), 156.0 (32.5%), 155.0 (8.8%), 157.0 (2.8%)
• ¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 8.00-7.92 (m, 2H), 7.68-7.58 (m, 1H), 7.57-7.45 (m, 2H), 4.72 (s, 2H).

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with 1-phenylethanone (360 mg, 350 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride was also added. (82.9 mg, 0.5 mmol) and copper(II) chloride dihydrate (34 mg, 0.2 mmol) were added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 9.0 ° F at a current density of 50 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS. To determine the yield, the product was quantified by GC using external calibration (yield: 43%, 199 mg, 1.3 mmol).

• m/z: 154.0 (100.0%), 156.0 (32.5%), 155.0 (8.8%), 157.0 (2.8%)
• ¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 8.00-7.92 (m, 2H), 7.68-7.58 (m, 1H), 7.57-7.45 (m, 2H), 4.72 (s, 2H).

Example 15: Methyl 2-chloroacetoacetate

According to the modified AAV1, hexachlorocyclohexane (145.5 mg, 0.5 mmol, 1.0 eq.) was dissolved with methyl acetoacetate (174 mg, 161 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (82.9 mg, 0.5 mmol) and copper(II) chloride dihydrate (17.0 mg, 0.1 mmol) were also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at a current density of 5.0 mA cm ^-2 at 6.0 F. Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS.
m/z: 150.0 (100.0%), 152.0 (32.7%), 151.0 (5.6%), 153.0 (1.8%)

IV. Production of chloro- and bromomethyl acetals in pot electrolysis Example 16: Chloroacetaldehyde dimethyl acetal (= 2-chloro-1,1-dimethoxyethane)

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with ethyl vinyl ether (219 mg, 290 µL, 3.0 mmol, 3.0 eq.) and methanol (387 mg, 490 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Additionally, tetraethylammonium chloride (41.4 mg, 0.25 mmol) was added. The solution was added and electrolyzed galvanostatically at 25 °C under room atmosphere and at 8.5 °F at a current density of 15.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS.
m/z: 124.0 (100.0%), 126.0 (32.5%), 125.0 (4.5%), 127.0 (1.5%)

Example 16a: 2-Chloro-1,1-dimethoxyethane

• m/z: 124.0 (100.0%), 126.0 (32.5%), 125.0 (4.5%), 127.0 (1.5%)
• ¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 4.51 (t, J = 5.4 Hz, 1H), 3.50 (d, J = 5.4 Hz, 2H), 3.40 (s, 6H).

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with ethyl vinyl ether (219 mg, 290 µL, 3.0 mmol, 3.0 eq.) and methanol (387 mg, 490 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 8.5 F at a current density of 15.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS. The product was then isolated from the electrolyte by distillation under reduced pressure. To determine the yield, the product was quantified by GC using external calibration (yield: 47%, 175 mg, 1.41 mmol).

• m/z: 124.0 (100.0%), 126.0 (32.5%), 125.0 (4.5%), 127.0 (1.5%)
• ¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.51 (t, J = 5.4 Hz, 1H), 3.50 (d, J = 5.4 Hz, 2H), 3.40 (s, 6H).

Example 17: Chloroacetaldehyde ethylmethyl acetal (= 2-chloro-1-ethoxyl-1-methoxyethane)

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with ethyl vinyl ether (219 mg, 290 µL, 3.0 mmol, 3.0 eq.) and methanol (387 mg, 490 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 8.5 F at a current density of 15.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS. To determine the yield, the product was quantified by GC using external calibration (yield: 19%, 79 mg, 0.57 mmol).
m/z: 138.0 (100.0%), 140.0 (32.4%), 139.0 (5.5%), 141.0 (1.8%)

Example 18: Chloroacetaldehyde diethyl acetal (2-chloro-1,1-di(ethoxy)ethane)

• m/z: 152.1 (100.0%), 154.1 (32.6%), 153.1 (6.7%), 155.1 (2.2%)
• ¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 4.62 (t, J = 5.5 Hz, 1H), 3.70 (dq, J = 9.4, 7.1 Hz, 2H), 3.58 (dq, J = 9.3, 7.0 Hz, 2H), 3.50 (d, J = 5.4 Hz, 2H), 1.22 (t, J = 7.1 Hz, 6H).

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with ethyl vinyl ether (219 mg, 290 µL, 3.0 mmol, 3.0 eq.) and ethanol (552 mg, 700 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 8.5 F at a current density of 15.0 mA cm-2. Isostatic graphite electrodes were preferably used as the anode and cathode. The product was analyzed by GC-MS. The product was then isolated from the electrolyte by distillation under reduced pressure. To determine the yield, the product was quantified by GC using external calibration (yield: 88%, 403 mg, 2.64 mmol).

• m/z: 152.1 (100.0%), 154.1 (32.6%), 153.1 (6.7%), 155.1 (2.2%)
• ¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.62 (t, J = 5.5 Hz, 1H), 3.70 (dq, J = 9.4, 7.1 Hz, 2H), 3.58 (dq, J = 9.3, 7.0 Hz, 2H), 3.50 (d, J = 5.4 Hz, 2H), 1.22 (t, J = 7.1 Hz, 6H).

Example 18a: 2-Chloro-1,1-di(ethoxy)ethane (HCl as non-preferred chlorine source)

According to the modified AAV1, concentrated hydrochloric acid (37%, 200 µL) was dissolved with ethyl vinyl ether (219 mg, 290 µL, 3.0 mmol, 3.0 eq.) and ethanol (552 mg, 700 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 8.5 F at a current density of 15.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS. To determine the yield, the product was quantified by GC using external calibration (yield: 30%, 139 mg, 0.91 mmol).
m/z: 152.1 (100.0%), 154.1 (32.6%), 153.1 (6.7%), 155.1 (2.2%)

Example 19: Chloroacetaldehyde ethylisopropyl acetal (= 2-(2-chloro-1-ethoxyethoxy)propane)

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with ethyl vinyl ether (219 mg, 290 µL, 3.0 mmol, 3.0 eq.) and isopropanol (721 mg, 925 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 8.5 F at a current density of 15.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS.
m/z: 166.1 (100.0%), 168.1 (32.6%), 167.1 (7.8%), 169.1 (2.5%)

Example 20: Chloroacetaldehyde diisopropyl acetal (= 1-chloro-2,2-di(methylethyloxy)ethane)

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with isopropyl vinyl ether (258 mg, 342 µL, 3.0 mmol, 3.0 eq.) and isopropanol (721 mg, 925 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 8.5 F at a current density of 15.0 mA cm-2. Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS.
m/z: 180.1 (100.0%), 182.1 (32.7%), 181.1 (8.9%), 183.1 (2.9%)

Example 21: 2-Chloromethyl-1,3-dioxolane

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with ethylene glycol vinyl ether (264 mg, 270 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) and manganese(II) chloride tetrahydrate (19.8 mg, 0.1 mmol) were also added to the solution and electrolyzed galvanostatically at 57 °C under room atmosphere and at a current density of 10.0 mA cm ^-2 , applying 7.4 F. Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS.
m/z: 122.0 (100.0%), 124.0 (32.4%), 123.0 (4.5%), 125.0 (1.5%)

Example 21a: 2-Chloromethyl-1,3-dioxolane

• m/z: 122.0 (100.0%), 124.0 (32.4%), 123.0 (4.5%), 125.0 (1.5%)
• ¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 5.14 (t, J = 4.0 Hz, 1H), 4.06-4.01 (m, 2H), 3.9-3.89 (m, 2H), 3.52 (d, J = 3.9 Hz, 2H).

According to the modified AAV1, hexachlorocyclohexane (218.1 mg, 0.75 mmol, 1.0 eq.) was dissolved with 2-hydroxyethyl vinyl ether (198 mg, 202 µL, 2.25 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was added to the solution and electrolyzed galvanostatically at 57 °C under room atmosphere and at 7.4 F at a current density of 10.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was then removed from the electrolyte by distillation under reduced pressure and subsequently fractionally distilled (yield: 35%, 97 mg, 0.79 mmol). The product was detected by GC-MS.

• m/z: 122.0 (100.0%), 124.0 (32.4%), 123.0 (4.5%), 125.0 (1.5%)
• ¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 5.14 (t, J = 4.0 Hz, 1H), 4.06-4.01 (m, 2H), 3.9-3.89 (m, 2H), 3.52 (d, J = 3.9 Hz, 2H).

Example 22: 2-Chloromethyl-1,3-dioxepane

• m/z: 150 (100.0%), 152 (32.6%), 151 (6.7%), 153 (2.2%)
• ¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 4.84 (t, J = 5.3 Hz, 1H), 3.93 (dq, J = 11.9, 3.4 Hz, 2H), 3.66 (dq, 2H), 3.46 (d, J = 5.3 Hz, 2H), 1.76-1.68 (m, 4H).

According to the modified AAV1, hexachlorocyclohexane (218.7 mg, 0.75 mmol, 1.0 eq.) was dissolved with tetramethylene glycol vinyl ether (= 4-hydroxybutyl vinyl ether) (261 mg, 276 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride was also added. (41.4 mg, 0.25 mmol) and manganese(II) chloride tetrahydrate (14.8 mg, 0.075 mmol) were added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 7.0 F at a current density of 10.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS. The product was then removed from the electrolyte by distillation under reduced pressure and subsequently fractionally distilled (yield: 79%, 276 mg, 1.78 mmol). To determine the yield, the product was also quantified by GC using external calibration.

• m/z: 150 (100.0%), 152 (32.6%), 151 (6.7%), 153 (2.2%)
• ¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.84 (t, J = 5.3 Hz, 1H), 3.93 (dq, J = 11.9, 3.4 Hz, 2H), 3.66 (dq, 2H), 3.46 (d, J = 5.3 Hz, 2H), 1.76-1.68 (m, 4H).

Example 22a: 2-Chloromethyl-1,3-dioxepane with HCl as non-preferred chlorine source

According to the modified AAV1, concentrated hydrochloric acid (37%, 100 µL) was dissolved with 4-hydroxybutyl vinyl ether (261 mg, 276 µL, 2.25 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) and manganese(II) chloride tetrahydrate (14.8 mg, 0.075 mmol) were also added to the solution and electrolyzed at 25 °C under room atmosphere and with a current density of 10.0 mA cm ^-2 at 7.0 F. Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS. To determine the yield, the product was quantified by GC using external calibration (yield: 26%, 87 mg, 0.58 mmol).

Example 23: 2-Chloromethyl-1,3,6-trioxocane

• m/z: 166.0 (100.0%), 168.0 (32.8%), 167.0 (6.7%), 169.0 (2.2%)
• ¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 4.77 (t, J = 5.4 Hz, 1H), 4.01-3.92 (m, 4H), 3.79-3.64 (m, 4H), 3.45 (d, J = 5.4 Hz, 2H).

According to the modified AAV1, hexachlorocyclohexane (218.7 mg, 0.75 mmol, 1.0 eq.) was dissolved with 2-[2-(ethenyloxy)ethoxy]ethanol (368 mg, 382 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) and manganese(II) chloride tetrahydrate (14.8 mg, 0.075 mmol) were added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at a current density of 10.0 mA cm ^-2 . As anode and cathode, Isostatic graphite electrodes were used. The product was detected by GC-MS. The product was then sublimed from the electrolyte under reduced pressure. To determine the yield, the product was quantified by GC using external calibration (yield: 38%, 142 mg, 0.86 mmol).

• m/z: 166.0 (100.0%), 168.0 (32.8%), 167.0 (6.7%), 169.0 (2.2%)
• ¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.77 (t, J = 5.4 Hz, 1H), 4.01-3.92 (m, 4H), 3.79-3.64 (m, 4H), 3.45 (d, J = 5.4 Hz, 2H).

Example 24: 2-Bromomethyl-1,3-dioxepane

• m/z: 194.0 (100.0%), 196.0 (97.9%), 195.0 (6.7%), 197.0 (6.5%)
• ¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 4.89 (t, J = 5.3 Hz, 1H), 3.93 (dq, J = 11.9, 3.5 Hz, 2H), 3.69-3.64 (m, 2H), 3.32 (d, J = 5.4 Hz, 2H), 1.76-1.68 (m, 4H).

According to the modified AAV1, hexabromocyclododecane (481 mg, 0.75 mmol, 1.0 eq.) was dissolved with 4-hydroxybutyl vinyl ether (261 mg, 276 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) and manganese(II) bromide tetrahydrate (21.4 mg, 0.075 mmol) were also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 7.0 F at a current density of 10.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was detected by GC-MS. The product was then isolated from the electrolyte by distillation under reduced pressure. To determine the yield, the product was quantified by GC using external calibration (yield: 29%, 131 mg, 0.67 mmol).

• m/z: 194.0 (100.0%), 196.0 (97.9%), 195.0 (6.7%), 197.0 (6.5%)
• ¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.89 (t, J = 5.3 Hz, 1H), 3.93 (dq, J = 11.9, 3.5 Hz, 2H), 3.69-3.64 (m, 2H), 3.32 (d, J = 5.4 Hz, 2H), 1.76-1.68 (m, 4H).

Example 25: 2,3-Dichloropropan-1-ol

• m/z: 218.0 (100.0%), 220.0 (64.3%), 222.0 (10.2%), 219.0 (9.8%), 221.0 (6.3%), 223.0 (1.0%)
• ¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 4.16 (ddd, J = 9.5, 7.8, 4.5 Hz, 1H), 3.96-3.91 (m, 2H), 3.85-3.75 (m, 2H), 2.16 (s, 1H).

According to the modified AAV1, hexachlorocyclohexane (3.635 g, 12.5 mmol, 1.0 eq.) was dissolved with allyl alcohol (2.178 g, 2.56 mL, 37.5 mmol, 3.0 eq.) in 50 mL of propylene carbonate. Tetraethylammonium chloride (414 mg, 2.5 mmol) and manganese(II) chloride tetrahydrate (495 mg, 2.5 mmol) were also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and with the application of 6.5 F at a current density of 11.7 mA cm ^-2 . Isostatic graphite electrodes (10 cm x 2.4 cm x 0.3 cm) were preferably used as the anode and cathode. The product was detected by GC-MS. To determine the yield, the product was quantified by GC using external calibration (yield: 79%, 3.82 g, 29.6 mmol).

• m/z: 218.0 (100.0%), 220.0 (64.3%), 222.0 (10.2%), 219.0 (9.8%), 221.0 (6.3%), 223.0 (1.0%)
• ¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.16 (ddd, J = 9.5, 7.8, 4.5 Hz, 1H), 3.96-3.91 (m, 2H), 3.85-3.75 (m, 2H), 2.16 (s, 1H).

Example 26: Chloroacetaldehyde dipropyl acetal (1-chloro-2,2-di(propoxy)ethane)

• m/z: 180.1 (100.0%), 182.1 (32.0%), 181.1 (8.9%), 183.1 (2.8%)
• ¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 4.62 (t, J = 5.5 Hz, 1H), 3.60 (dt, J = 9.3, 6.7 Hz, 2H), 3.51 (d, J = 5.5 Hz, 2H), 3.46 (dt, J = 9.2, 6.7 Hz, 2H), 1.65-1.58 (h, 4H), 0.94 (t, J = 7.4 Hz, 6H).

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with propyl vinyl ether (258 mg, 340 µL, 3.0 mmol, 3.0 eq.) and propanol (721 mg, 900 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and with an application of 8.5 F at a current density of 15.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was also detected by GC-MS. The product was then isolated from the electrolyte by distillation under reduced pressure. To determine the yield, the product was quantified by GC using external calibration (yield: 42%, 233 mg, 1.29 mmol).

• m/z: 180.1 (100.0%), 182.1 (32.0%), 181.1 (8.9%), 183.1 (2.8%)
• ¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.62 (t, J = 5.5 Hz, 1H), 3.60 (dt, J = 9.3, 6.7 Hz, 2H), 3.51 (d, J = 5.5 Hz, 2H), 3.46 (dt, J = 9.2, 6.7 Hz, 2H), 1.65-1.58 (h, 4H), 0.94 (t, J = 7.4 Hz, 6H).

Example 27: Chloroacetaldehyde dichloroethanol acetal (2-chloro-1,1-di(2-chloroethoxy)ethane)

• m/z: 220.0 (100.0%), 222.0 (95.9%), 224.0 (31.0%), 221.0 (6.7%), 223.0 (6.3%), 226.0 (3.3%), 225.0 (2.1%)
• ¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 4.80 (t, J = 5.6 Hz, 1H), 3.93 (dt, J = 11.2, 5.6 Hz, 2H), 3.84 (dt, J = 10.8, 5.6 Hz, 2H), 3.66 (t, J = 5.7 Hz, 4H), 3.57 (d, J = 5.5 Hz, 2H).

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with 2-chloroethyl vinyl ether (320 mg, 304 µL, 3.0 mmol, 3.0 eq.) and 2-chloroethanol (966 mg, 798 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 8.5 F at a current density of 15.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was also detected by GC-MS. The solvent was removed under reduced pressure. The product was then isolated from the residue by fractional distillation. To determine the yield, the product was quantified by GC using external calibration (yield: 46%, 306 mg, 1.38 mmol).

• m/z: 220.0 (100.0%), 222.0 (95.9%), 224.0 (31.0%), 221.0 (6.7%), 223.0 (6.3%), 226.0 (3.3%), 225.0 (2.1%)
• ¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.80 (t, J = 5.6 Hz, 1H), 3.93 (dt, J = 11.2, 5.6 Hz, 2H), 3.84 (dt, J = 10.8, 5.6 Hz, 2H), 3.66 (t, J = 5.7 Hz, 4H), 3.57 (d, J = 5.5 Hz, 2H).

Example 28: Chloroacetaldehyde dibutyl acetal (2-chloro-1,1-di(butoxy)ethane)

• m/z: 208.1 (100.0%), 210.1 (32.0%), 209.1 (11.1%), 211.1 (3.5%), 210.1 (1.0%)
• ¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 4.60 (t, J = 5.4 Hz, 1H), 3.63 (dt, J = 9.2, 6.5 Hz, 2H), 3.53-3.47 (m, 4H), 1.57 (dq, J = 8.4, 6.6 Hz, 4H), 1.43-1.34 (m, 4H), 0.92 (t, J = 7.3 Hz, 6H).

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with butyl vinyl ether (300 mg, 390 µL, 3.0 mmol, 3.0 eq.) and butanol (889 mg, 1098 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 8.5 F at a current density of 15.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was also detected by GC-MS. The electrolyte was extracted with pentane. After removal of the solvent, the product was then separated from the The residue was isolated. To determine the yield, the product was quantified by GC using external calibration (yield: 49%, 307 mg, 1.47 mmol).

• m/z: 208.1 (100.0%), 210.1 (32.0%), 209.1 (11.1%), 211.1 (3.5%), 210.1 (1.0%)
• ¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.60 (t, J = 5.4 Hz, 1H), 3.63 (dt, J = 9.2, 6.5 Hz, 2H), 3.53-3.47 (m, 4H), 1.57 (dq, J = 8.4, 6.6 Hz, 4H), 1.43-1.34 (m, 4H), 0.92 (t, J = 7.3 Hz, 6H).

Example 28a: 2-Chloro-1,1-di(butoxy)ethane (HCl as non-preferred chlorine source)

According to the modified AAV1, concentrated hydrochloric acid (37%, 100 µL) was dissolved with butyl vinyl ether (300 mg, 390 µL, 3.0 mmol, 3.0 eq.) and butanol (889 mg, 1098 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and with an application of 8.5 F at a current density of 15.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was also detected by GC-MS. To determine the yield, the product was quantified by GC using external calibration (yield: 12%, 75 mg, 0.36 mmol).

Example 29: Chloroacetaldehyde diisobutyl acetal (2-chloro-1,1-di(2-methylpropoxy)ethane)

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with 2-methylpropyl vinyl ether (300 mg, 390 µL, 3.0 mmol, 3.0 eq.) and 2-methylpropanol (889 mg, 1112 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 8.5 F at a current density of 15.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was also detected by GC-MS. The electrolyte was extracted with pentane. After removal of the solvent, the product was isolated from the residue by fractional distillation. For the determination of the yield, the Product quantified by GC using external calibration (yield: 56%, 351 mg, 1.68 mmol).

Example 29a: 2-Chloro-1,1-di(2-methylpropoxy)ethane (HCl as non-preferred chlorine source)

• m/z: 208.12 (100.0%), 210.12 (32.0%), 209.13 (11.1%), 211.12 (3.5%), 210.13 (1.0%)
• ¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 4.60 (t, J = 5.5 Hz, 1H), 3.51 (d, J = 5.4 Hz, 2H), 3.40 (dd, J = 9.0, 6.6 Hz, 2H), 3.26 (dd, J = 9.0, 6.7 Hz, 2H), 1.86 (dp, J = 13.3, 6.7 Hz, 2H), 0.92 (d, J = 6.7 Hz, 12H).

According to the modified AAV1, concentrated hydrochloric acid (37%, 100 µL) was dissolved with butyl vinyl ether (300 mg, 390 µL, 3.0 mmol, 3.0 eq.) and ^i- butanol (889 mg, 1112 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 8.5 F at a current density of 15.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. To determine the yield, the product was quantified by GC using external calibration (yield: 17%, 104 mg, 0.50 mmol).

• m/z: 208.12 (100.0%), 210.12 (32.0%), 209.13 (11.1%), 211.12 (3.5%), 210.13 (1.0%)
• ¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.60 (t, J = 5.5 Hz, 1H), 3.51 (d, J = 5.4 Hz, 2H), 3.40 (dd, J = 9.0, 6.6 Hz, 2H), 3.26 (dd, J = 9.0, 6.7 Hz, 2H), 1.86 (dp, J = 13.3, 6.7 Hz, 2H), 0.92 (d, J = 6.7 Hz, 12H).

Example 30: Chloroacetaldehyde dibenzyl acetal (2-chloro-1,1-di(benzyloxy)ethane)

• m/z: 276.1 (100.0%), 278.1 (32.0%), 277.1 (17.6%), 279.1 (5.6%), 278.1 (1.9%)
• ¹H-NMR (400 MHz, CD₂Cl₂) δ [ppm] = 7.41-7.29 (m, 10H), 4.88 (t, J = 5.4 Hz, 1H), 4.72 (d, J = 11.6 Hz, 2H), 4.63 (d, J = 11.6 Hz, 2H), 3.64 (d, J = 5.5 Hz, 2H).

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with benzyl vinyl ether (403 mg, 415 µL, 3.0 mmol, 3.0 eq.) and benzyl alcohol (1298 mg, 1248 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 8.5 F at a current density of 15.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was also detected by GC-MS. The solvent was removed under reduced pressure. The product was then isolated from the residue by fractional distillation. To determine the yield, the product was quantified by GC using external calibration (yield: 31%, 260 mg, 0.93 mmol).

• m/z: 276.1 (100.0%), 278.1 (32.0%), 277.1 (17.6%), 279.1 (5.6%), 278.1 (1.9%)
• ¹ H-NMR (400 MHz, CD ₂ Cl ₂ ) δ [ppm] = 7.41-7.29 (m, 10H), 4.88 (t, J = 5.4 Hz, 1H), 4.72 (d, J = 11.6 Hz, 2H), 4.63 (d, J = 11.6 Hz, 2H), 3.64 (d, J = 5.5 Hz, 2H).

Example 31: 2-Chloromethyl-1,3-dioxane

According to the modified AAV1, hexachlorocyclohexane (218.1 mg, 0.75 mmol, 1.0 eq.) was dissolved with 3-hydroxypropyl vinyl ether (230 mg, 239 µL, 2.25 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) and manganese(II) chloride tetrahydrate (14.8 mg, 0.075 mmol) were also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 7.0 F at a current density of 10.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was then removed from the electrolyte by distillation under reduced pressure. The product was detected by ¹ H-NMR in the distillation fraction and by GC-MS.

Example 32: Bromoacetaldehyde dimethyl acetal (2-bromo-1,1-di(methoxy)ethane)

According to the modified AAV1, 1,2,5,6,9,10-hexabromocyclododecane (641.7 mg, 1.0 mmol, 1.0 eq.) was dissolved with ethyl vinyl ether (219 mg, 290 µL, 3.0 mmol, 3.0 eq.) and methanol (387 mg, 490 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and with the application of 8.5 F at a current density of 15.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was then removed from the electrolyte by distillation under reduced pressure. isolated. To determine the yield, the product was quantified by GC using external calibration (yield: 22%, 109 mg, 0.65 mmol).

¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.55 (t, J = 5.4 Hz, 1H), 3.39 (s, 6H), 3.36 (d, J = 5.5 Hz, 2H).

Example 33: Bromoacetaldehyde diethyl acetal (2-bromo-1,1-di(ethoxy)ethane)

According to the modified AAV1, 1,2,5,6,9,10-hexabromocyclododecane (641.7 mg, 1.0 mmol, 1.0 eq.) was dissolved in 5 mL of propylene carbonate with ethyl vinyl ether (219 mg, 290 µL, 3.0 mmol, 3.0 eq.) and ethanol (552 mg, 700 µL, 12.0 mmol, 12.0 eq.). Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and with an application of 8.5 F at a current density of 15.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was then isolated from the electrolyte by distillation under reduced pressure. To determine the yield, the product was quantified by GC using external calibration (yield: 86%, 510 mg, 2.59 mmol).

¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.66 (t, J = 5.5 Hz, 1H), 3.72-3.55 (m, 4H), 3.36 (d, J = 5.5 Hz, 2H), 1.23 (t, J = 7.1 Hz, 6H).

Example 34: Bromoacetaldehyde dipropyl acetal (2-bromo-1,1-di(propoxy)ethane)

According to the modified AAV1, 1,2,5,6,9,10-hexabromocyclododecane (641.7 mg, 1.0 mmol, 1.0 eq.) was dissolved with propyl vinyl ether (258 mg, 340 µL, 3.0 mmol, 3.0 eq.) and ^n- propanol (721 mg, 900 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 8.5 F at a current density of 15.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The electrolyte was extracted with pentane. After removal of the solvent, the The product was isolated from the residue by fractional distillation. To determine the yield, the product was quantified by GC using external calibration (yield: 14%, 94 mg, 0.419 mmol).

¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.66 (t, J = 5.5 Hz, 1H), 3.62-3.44 (m, 4H), 3.37 (d, J = 5.5 Hz, 2H), 1.66-1.58 (m, 4H), 0.94 (t, J = 7.5 Hz, 6H).

Example 35: Bromoacetaldehyde diisobutyl acetal (2-bromo-1,1-di(2-methylpropoxy)ethane)

According to the modified AAV1, 1,2,5,6,9,10-hexabromocyclododecane (641.7 mg, 1.0 mmol, 1.0 eq.) was dissolved with 2-methylpropyl vinyl ether (300 mg, 390 µL, 3.0 mmol, 3.0 eq.) and 2-methylpropanol (889 mg, 1112 µL, 12.0 mmol, 12.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere and at 8.5 F at a current density of 15.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The electrolyte was extracted with pentane. After removal of the solvent, the product was isolated from the residue by fractional distillation. To determine the yield, the product was quantified by GC using external calibration (yield: 36%, 273 mg, 1.08 mmol).

¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.65 (t, J = 5.6 Hz, 1H), 3.42-3.37 (m, 4H), 3.25 (dd, J = 9.0, 6.6 Hz, 2H), 1.87 (dp, J = 13.3, 6.7 Hz, 2H), 0.93 (d, J = 6.7 Hz, 12H).

Example 36: 2-Bromomethyl-1,3-dioxolane

According to the modified AAV1 as follows, 1,2,5,6,9,10-hexabromocyclododecane (641.7 mg, 1.0 mmol, 1.0 eq.) was treated with 2-hydroxyethyl vinyl ether (264 mg, 270 µL, 3.0 mmol, 3.0 eq.) was dissolved in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was also added to the solution and electrolyzed at 57 °C under room atmosphere and with the application of 7.4 F galvanostatically at a current density of 10.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was then isolated from the electrolyte by distillation under reduced pressure. To determine the yield, the product was quantified by GC using external calibration (yield: 49%, 245 mg, 1.47 mmol).

¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 5.14 (t, J = 4.1 Hz, 1H), 4.07-3.93 (m, 4H), 3.39 (d, J = 4.2 Hz, 2H).

V. Production of monohalogenated products in batch processes Example 37: 2-Chloroethyl acetate

• m/z: 122.0 (100.0%), 124.0 (32.4%), 123.0 (4.5%), 125.0 (1.5%)
• ¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 4.30 (t, J = 5.5 Hz, 2H), 3.66 (t, J = 5.5 Hz, 2H), 2.08 (s, 3H).

According to the modified AAV1, hexachlorocyclohexane (290.8 mg, 1.0 mmol, 1.0 eq.) was dissolved with ethylene glycol vinyl ether (264 mg, 270 µL, 3.0 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was added to the solution and electrolyzed galvanostatically at 8 °C under room atmosphere and at 7.4 F at a current density of 5.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was then removed from the electrolyte by distillation under reduced pressure. The product was detected by GC-MS. To determine the yield, the product was quantified by GC using external calibration (yield: 94%, 259 mg, 2.12 mmol).

• m/z: 122.0 (100.0%), 124.0 (32.4%), 123.0 (4.5%), 125.0 (1.5%)
• ¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.30 (t, J = 5.5 Hz, 2H), 3.66 (t, J = 5.5 Hz, 2H), 2.08 (s, 3H).

Example 38: 3-Chloropropyl acetate

• m/z: 136.03 (100.0%), 138.03 (32.4%), 137.03 (5.5%), 139.03 (1.8%)
• ¹H-NMR (400 MHz, CDCl₃) δ [ppm] = 4.20 (t, J = 6.1 Hz, 2H), 3.60 (t, J = 6.4 Hz, 2H), 2.11-2.03 (m, 5H).

According to the modified AAV1, hexachlorocyclohexane (218.1 mg, 0.75 mmol, 1.0 eq.) was dissolved with 3-hydroxypropyl vinyl ether (230 mg, 239 µL, 2.25 mmol, 3.0 eq.) in 5 mL of propylene carbonate. Tetraethylammonium chloride (41.4 mg, 0.25 mmol) was also added to the solution and electrolyzed galvanostatically at 25 °C under room atmosphere using 7 F at a current density of 10.0 mA cm ^-2 . Isostatic graphite electrodes were preferably used as the anode and cathode. The product was then removed from the electrolyte by distillation under reduced pressure. The product was detected by GC-MS. To determine the yield, the product was quantified by GC using external calibration (yield: 60%, 186 mg, 1.36 mmol).

• m/z: 136.03 (100.0%), 138.03 (32.4%), 137.03 (5.5%), 139.03 (1.8%)
• ¹ H-NMR (400 MHz, CDCl ₃ ) δ [ppm] = 4.20 (t, J = 6.1 Hz, 2H), 3.60 (t, J = 6.4 Hz, 2H), 2.11-2.03 (m, 5H).

Claims (17)

Process for the chlorination or bromination of organic compounds V which have at least one olefinically unsaturated double bond or at least one enolizable functional group, comprising the electrolysis of a liquid reaction mixture containing the organic compound V as halogen acceptor compound, at least one halogen source containing chlorine or bromine, at least one solvent and at least one conducting salt in an undivided electrolysis cell, wherein the solvent comprises at least one organic carbonate. The process according to claim 1, wherein the organic carbonate is selected from the group of di-C ₁ -C ₄ alkyl carbonates and C ₂ -C ₄ alkylene carbonates. The process of claim 2, wherein the organic carbonate is propylene carbonate. A process according to any one of the preceding claims, wherein the organic carbonate constitutes at least 50% by weight of the total amount of solvents in the liquid reaction mixture. Process according to one of the preceding claims, wherein the liquid reaction mixture comprises at least one further solvent selected from water, C ₁ -C ₄ alkanols, C ₁ -C ₄ fluoroalkanols, C ₁ -C ₄ alkylnitriles, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, C ₁ -C ₄ alkylpyrrolidone, C ₁ -C ₄ alkyl esters of C ₂ -C ₄ alkanoic acids, C ₁ -C ₄ alkyl esters of C ₂ -C ₄ hydroxyalkanoic acids, C ₁ -C ₄ chloroalkanes, dihydrolevoglucosenone and mixtures thereof. A process according to any one of the preceding claims, wherein the halogen source comprises an organic chlorine compound and/or an organic bromine compound. A process according to claim 6, wherein the organic chlorine compound or the organic bromine compound has at least two vicinally bonded chlorine atoms or at least 2 vicinally bonded bromine atoms. The process of claim 7, wherein the halogen source is selected from 1,2,3,4,5,6-hexachlorocyclohexane and 1,2,5,6,9,10-hexabromocyclododecane. Process according to one of the preceding claims, wherein the compound V is selected from alkenols, alkenyl esters of aliphatic, cycloaliphatic or aromatic carboxylic acids, olefins, conjugated dienes, alkenyl ethers of aliphatic, cycloaliphatic or aromatic alcohols, olefinically unsaturated ketones, olefinically unsaturated carboxylic acids, olefinically unsaturated carboxylic acid esters, olefinically unsaturated lactones and olefinically unsaturated carbonates. Process according to one of the preceding claims, wherein the compound V is selected from 1-alkenyl esters of aliphatic, cycloaliphatic or aromatic carboxylic acids, 1-alkylenyl ethers of aliphatic, cycloaliphatic or aromatic alcohols, mono-olefinically unsaturated lactones in which a vinyl C atom of the olefinic double bond is bonded to the ring oxygen atom of the lactone, and olefinically unsaturated carbonates in which at least one vinyl C atom of the olefinic double bond is bonded to an oxygen atom of the carbonate group. Process according to one of claims 1 to 9, wherein the compound V is selected from aliphatic, alicyclic or aliphatic-aromatic ketones, aliphatic and alicyclic aldehydes, and aliphatic or cycloaliphatic 1,3-diketones and aliphatic and cycloaliphatic 3-ketocarboxylic acid esters. Process according to one of the preceding claims, wherein the concentration of compound V in the liquid reaction mixture is in the range of 5 to 100 g/L and wherein the concentration of the halogen source in the liquid reaction mixture is in the range of 5 to 300 g/L. Process according to one of the preceding claims, wherein the conducting salt is selected from quaternary ammonium salts, pyridinium salts, imidazolium salts, quaternary phosphonium salts and mixtures thereof, wherein the anions of the conducting salt are in particular selected from chloride, bromide, tetrafluoroborate, trifluoromethanesulfonate, tosylate, sulfate, C ₁ -C ₄ alkyl sulfate, perchlorate, acetate, hexafluorophosphate, bis(trifluoromethylsulfonyl)imide, nitrate, carbonate and bromate and in particular from chloride and bromide. The process according to claim 13, wherein the concentration of the conducting salt in the reaction mixture is in the range of 0.02 to 0.1 mol/L. Process according to one of the preceding claims, wherein the liquid reaction mixture contains at least one transition metal salt which is in particular selected from Mn(II) salts, Cu(I) salts, Cu(II) salts, Co(II) salts, Ni(II) salts, Cr(II) salts, Cr(III) salts, V(III) salts, Fe(II) salts, Fe(III) salts, Ru(III) salts, Rh(III) salts, Ir(III) salts, Pd(II) salts and combinations thereof. A process according to claim 15, wherein the liquid reaction mixture contains the transition metal salt in a concentration of up to 20 mol%, based on the amount of halogen source used. Method according to one of the preceding claims, wherein the anode material of the electrolysis cell is selected from graphite, glassy carbon, platinum, boron-doped diamond and mixed metal oxides comprising at least one metal oxide from the group ruthenium oxide, iridium oxide and tantalum oxide.