RU2423553C2 - Electrochemical method of producing halogenated compound containing carbonyl group - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing a halogenated carbonyl group-containing compound via electrochemical reaction of the corresponding carbonyl group-containing compound with a hydrogen halide H-X, an organic halide R'-X and/or a halide salt Mⁿ⁺-X_n ^- under substantially water-free conditions, wherein X is a chlorine, bromine or iodine atom, R' is an alkyl or aryl group which can be linear or branched, optionally containing one or more heteroatoms such as oxygen, nitrogen, chloride, bromide, fluoride or iodide from which the halogen atom X can be electrochemically split off, Mⁿ⁺ is a quaternary ammonium, alkali-earth metal, alkali metal or metal cation, and n is an integer ranging from 1 to 5, depending on the valence of the metal cation Mⁿ⁺.

EFFECT: method does not require additional processing of by-products formed, ensures low content of poly-halogenated by-products and easy halogenation of compounds containing a carbonyl group or hydrogen.

13 cl, 2 dwg, 9 tbl, 21 ex

Description

The invention relates to a new electrochemical method for producing a halogenated compound containing a carbonyl group, such as a carboxylic acid. In a particular embodiment, it relates to the chlorination of acetic acid to produce monochloracetic acid.

In industry, monochloracetic acid is obtained by reacting acetic acid with chlorine. This method of producing monochloracetic acid is widely known and a reactor is usually used in which a mixture of liquid acetic acid (HAc) reacts with chlorine gas under anhydrous conditions. A large number of compounds can be used to create such anhydrous conditions. If acetic anhydride is used, it will immediately be converted by hydrochloric acid into acetyl chloride, which is the catalyst for this process. The process is usually carried out at a pressure of 1 to 6 bar abs. and temperature from 80 to 180 ° C. In the reactor, monochloracetic acid (MCA) and gaseous HCl are formed together with by-products, examples of which are dichloroacetic acid (DCA) and trichloroacetic acid (TCA).

After the MCA-containing reaction product mixture has passed through the reactor (s) and the catalyst regeneration section, DCA is present in a significant amount, usually about 3-10%. The product mixture containing MCA / DCA is then fed to the unit to reduce the amount of DCA in the MCA. This can be done by physical separation, such as melt crystallization, or by chemical conversion, such as reduction, when DCA is reduced with hydrogen in the presence of a hydrogenation catalyst, for example a metal based catalyst. This catalyst not only restores DCA, but also to some extent restores MCA, which, of course, is undesirable. In addition, such a recovery facility and its operation are expensive, and this increases the cost of obtaining the final MCA product.

Then, low boiling components are removed from the MCA by conventional vacuum distillation.

A method for producing MCA by an electrochemical process was described by A. Youtz et al., "Depolarization of the Chlorine Electrode by Organic Compounds" in J. Am. Chem. Soc. , 1924, 46, 549. The method comprises reacting 70% acetic acid in an aqueous solution with hydrochloric acid to produce chloroacetic acid.

The electrochemical method for producing a halogenated carboxylic acid (derivative) in an aqueous medium has the disadvantage that a low amount of the desired (mono) halogenated carboxylic acid is formed. In addition, in a chloride aqueous medium, the main product of electrolysis is often chlorine gas, which is undesirable, since this means an additional waste stream and, in addition, the combination of chlorine gas and hydrogen gas can make the mixture of exhaust gases reaction explosive.

The aim of the invention is to provide a method for producing a halogenated compound containing a carbonyl group, using raw materials that are cheap and available on a large scale, and at the same time, additional processing of the resulting by-products is not required. In addition, it is an object of the present invention to provide a process in which a carbonyl group-containing monohalogenated compound provides a reduced content of di-, tri- or polyhalogenated by-products compared to the above-described industrial process. Another objective of the invention is to provide a method that can be easily implemented on existing equipment used for the above-described modern industrial method without requiring harsh physical conditions. The next goal is to develop a method that provides a compound containing a carbonyl group that is selectively halogenated at the position of an α-carbon atom (i.e., the carbon atom closest to the carbonyl group). Another goal is to develop a method that provides an improved yield of the product, for example, compared with the aqueous electrochemical method of Youtz et al. And which provides valuable byproducts.

The present invention now provides a process for preparing a halogenated compound containing a carbonyl group by electrochemical reaction of the corresponding compound containing a carbonyl group with HX hydrohalide, R'-X organic halide and / or M ^{n +} -X _n ^" halide salt under substantially anhydrous conditions, wherein X is a chlorine, bromine or iodine atom, R 'is an alkyl or aryl group which may be linear or branched, optionally containing one or more heteroatoms, such as hydrogen, nitrogen; chloride, bromide, fluoride or iodide, from which the halogen atom X can be easily removed electrochemically, M ^{n +} is a quaternary ammonium, alkaline earth metal, alkali metal or metal cation, and n is an integer from 1 to 5, depending from the valency of the metal cation M ^{n +} .

Essentially anhydrous conditions are defined as conditions under which the reaction mixture contains less than 1 wt.% Water, preferably less than 0.1 wt.%, More preferably about zero, most preferably, the conditions are completely anhydrous, which is achieved when the reaction the mixture contains compounds that act as water absorbers.

Unexpectedly, it turned out that halogen X can only be selected from the group of chlorine, bromine and iodine, since fluorination is not possible using the method of the present invention. In the prior art (see, for example, P. Sartori, N. Ignat'ev, "The Actual state of our knowledge about the mechanism of electrochemical fluorination in anhydrous hydrogen fluoride (Simons process)", Journal of Fluorine Chemistry 87 (1998), pp 157-162, a method for fluorinating several organic compounds is described, however, these reactions usually lead to polyfluorination and do not provide selective fluorination at the α-carbon atom.

When applying the method according to the invention, no gaseous halogen (such as chlorine gas) is required, but instead a hydrohalide, organic halides or halide salts can be used, which are generally much more affordable and cheaper than the starting materials of a modern industrial process. The method of the present invention, as reaction products, gives a halogenated compound containing a carbonyl group and hydrogen. Any unreacted source of halide can be easily reused; the same is true for an unreacted compound with a carbonyl group. The resulting hydrogen by-product can be easily isolated and can be used, for example, as an energy source or starting compound for other chemical processes, that is, it has industrial value.

It was unexpectedly found that only a very small amount of di- and / or more halogenated compounds containing a carbonyl group was formed; it was found that when the carboxylic acid was halogenated, the amount of dihalogenated carboxylic acid was below 0.3 wt.%, and the amount of trihalogenated or more halogenated carboxylic acid, if any, was below the detection limit (i.e., 50 ppm). Since hydrogen gas (namely bubbles) is a by-product of the reaction, the reaction mixture remains well mixed and no mixing is required, which is also advantageous.

In the method according to the invention, an 80% electric current yield was achieved to obtain a monohalogenated carboxylic acid (derivative). It is expected that an even higher current efficiency can be achieved. In contrast, electrochemical chlorination of acetic acid in an aqueous medium results in a low yield, typically below 1%.

The current efficiency (also called current efficiency) is described in Bard-Stratman, Encyclopedia of Electrochemistry, Organic Electrochem. , Vol. 8, Chapter 2,3.1, p. 31 to which reference is made. In short, efficiency by current, or current output, means the fraction of current in the cell or (integrated over time) the fraction of the transferred charge that is used to form the product.

It was unexpectedly discovered that in the method according to the invention, di- and / or more halogenated compounds containing a carbonyl group are also effectively converted into a monohalogenated compound containing a carbonyl group. Accordingly, in one embodiment, the starting material may be a mixture of compounds containing at least di- and / or more halogenated compounds with carbonyl groups (R'-X) and a non-halogenated compound containing a carbonyl group, wherein the amount of di- and / or more halogenated compounds with carbonyl groups, preferably no more than equimolar to the amount of non-halogenated compound containing a carbonyl group. It was found that the use of such an initial mixture nevertheless leads to a reaction product containing mainly a monohalogenated compound with a carbonyl group, or, in other words, to a very low amount of di- and / or more halogenated compounds containing a carbonyl group. The hydrohalide is obtained in situ by the electrochemical reaction of a di- and / or more halogenated compound containing a carbonyl group at the cathode under electrochemical conditions.

In two documents, namely: LN Nekrasov et al., "Effect of small amouts of tetramethyl- and tetraethylamonium ions on electroreduction kinetics of certain organic compounds in solutions of tetrabuthylamonium salts", Elektrokhimiya , Vol. 24, No. 4, pp. 560-563, 1988 and A. Inesi, L. Rampazzo, "Electrochemical reduction of halogen containing compounds at a mercury cathode: chloroacetic, dichloroacetic acids and corresponding ethylesters in dimethylformamide", Electroanalytical Chemistry and Interfacial Electrochemistry, 44 (1973), pp. 25-35, it is disclosed that trichloroacetic acid can be reduced to dichloroacetic acid using an electrochemical process, but it is neither disclosed nor suggested that this compound can be used as a halogen source (i.e., as R'-X defined above) for halogenating the carbonyl group containing compound to obtain a monohalogenated carbonyl group containing compound.

Thus, in one embodiment, the invention provides a method in which the organic halide R'-X is a di- and / or more halogenated compound containing a carbonyl group, or, in other words, a method for producing a halogenated compound containing a carbonyl group, by electrochemical reaction of the corresponding a compound containing a carbonyl group with a di- and / or more halogenated compound containing a carbonyl group, optionally HX hydrohalide, an additional organic halogen R'-X and / or the halide salt M ^{n +} -X _n ^- , under substantially anhydrous conditions, wherein X is a chlorine, bromine or iodine atom, R 'is an alkyl or aryl group which may be linear or branched, containing ( optionally) one or more heteroatoms, such as oxygen, nitrogen; chloride, bromide, fluoride or iodide, from which the halogen atom X can be removed electrochemically, M ^{n +} means a quaternary ammonium cation, alkaline earth metal, alkali metal or metal, and n is an integer from 1 to 5, depending on the valency of the metal cation M ^{n +} .

The method of the invention can also be used as a second step in a conventional process for producing a monohalogenated compound containing a carbonyl group by chemical reaction of a compound containing a carbonyl group and a source of halogen. The method according to the invention can also be used to treat a mother liquor, which is obtained, for example, when the monohalogenated carboxylic acid (derivative) is separated from the reaction mixture containing both monohalogenated and di- and / or more halogenated carboxylic acids (derivatives), moreover, If such a mother liquor contains a mixture of the remaining monohalogenated carboxylic acid (derivative) and a relatively large amount of di- and / or more halogenated carboxylic acids (or their s).

Separation methods include conventional separation methods available to one skilled in the art, such as distillation, extraction and crystallization, with crystallization being most preferred.

In this regard, the invention provides a method for producing a halogenated compound containing a carbonyl group, first bringing a compound containing a carbonyl group into a chemical reaction with chlorine, bromine or iodine molecules and then electrochemically treating the reaction mixture in accordance with the above-described electrochemical method, the invention provides a method, in which the initial mixture is a mother liquor obtained by separating a monohalogenated compound containing a carbonyl group from the reaction mixture and monohalogenated compound containing both a carbonyl group and a di- and / or more halogenated compounds having a carbonyl group.

In a process with a mixture of a compound containing a carbonyl group and corresponding di- and / or more halogenated compounds containing a carbonyl group, the resultant reaction is the reaction of a di- and / or more halogenated compound containing a carbonyl group with a corresponding compound containing a carbonyl group, giving a monohalogenated compound containing a carbonyl group.

An embodiment comprising a conventional process followed by an electrochemical process according to the invention has the important advantage that the products of a conventional process (i.e., a hydrohalide and a mixture of a compound containing a carbonyl group, a monohalogenated compound containing a carbonyl group, and di- and / or more halogenated compounds containing a carbonyl group) are the starting material for the electrochemical stage. Thus, processing a product stream of a conventional process is not required; on the contrary, the product stream from a conventional process can be directly used as a feed stream at the electrochemical stage.

Accordingly, “more highly halogenated” means that up to 10, preferably from 3 to 6, chlorine, bromine and / or iodine atoms are present in the compound containing the carbonyl group.

In addition, the invention provides a device for implementing the above methods. In this regard, a device is provided that includes a chemical reactor (A) connected to an electrochemical reactor (B) via line (5) and, optionally, through lines (2), (3) and (4), wherein reactor (B) is connected with setting (C) of physical separation along line (9). The device is shown in figure 1.

The chemical reactor (A) may be a reaction apparatus (e.g., heated, and / or cooled, and / or insulated) of a suitable material (e.g., enamelled steel). Preferably, the chemical reactor comprises internal devices such as mechanical mixers, heat exchangers, inlet pipes (for example, for raw materials and return flows), and / or comprises sensors (such as temperature sensors, pressure sensors, liquid level sensors). Additionally, the chemical reactor (A) may include a UV irradiation device, such as a UV lamp, for converting gaseous halogen to a halogen atom.

In more detail, as shown in FIG. 1 halide, a compound containing a carbonyl group, optionally a catalyst and optionally an electrolyte are fed to the chemical reactor (A) via lines (1), (2), (3) and (4), respectively, two or more of which can be combined into one line for reaction with the intermediate product supplied to the electrochemical reactor (B) via line (5). Gaseous components formed in the chemical reactor (A) and removed from it can (optionally) be introduced partially or completely into the electrochemical reactor (B) also via line (6), in which case line (6) can be combined with line (5) ) in one line. Optionally, more or even all compounds containing a carbonyl group, a catalyst and an electrolyte can be supplied to the electrochemical reactor (B) through the inputs (2), (3) and (4), respectively, two or more of which can be combined into one input. In one embodiment, the electrochemical reactor (B) may be provided with an additional inlet stream (7) containing a halide (gas or liquid).

An electrochemical reactor (B) is a device comprising at least one anode and at least one cathode of any suitable material as described above, and is preferably an apparatus where the arrangement of the anode (s) and cathode (s) has a suitable geometry (e.g. , parallel plates or concentric cylinders, bathtubs with a sealed or fluidized interelectrode space). In a more preferred embodiment, the electrochemical reactor comprises one or more electrolyte separators, such as diaphragms or membranes. In another preferred embodiment, the electrochemical reactor (B) is a reactor containing parallel electrodes in an apparatus with or without internal and external liquid recirculation. The anode and cathode are connected to a direct current supply that supplies electric current to the electrodes. The electrodes can be connected to a power source in a monopolar or bipolar arrangement. In a preferred embodiment, monohalogenated compounds are simultaneously formed in the electrochemical reactor (B) as a result of halogenation of the feed at the anode and dehalogenation of the di or more halogenated compounds at the cathode occurs. In some embodiments, gaseous hydrogen is generated at the cathode in an electrochemical reactor, which is removed from the reactor via line (8).

A substantially reduced di- and / or more halogenated product from the electrochemical reactor (B) is supplied to the physical separation unit (C) via line (9). The hydrohalide and other components formed in the chemical reactor (A) and / or the electrochemical reactor (B) are separated from the product through line (11) and returned to the chemical reactor (A) and / or electrochemical reactor (B) via line (10) . In addition, the electrolyte can be supplied to the chemical reactor (A) and / or the electrochemical reactor (B) through the inlet (4), and the electrolyte can be separated from the reaction products and reagents in the physical separation unit (C) and, if necessary, can be returned to reactors A and B along lines (10).

Physical separation unit (C) is a device that may contain one or more distillation columns, extraction columns, absorption columns, or a combination thereof, suitable for separating the product of an electrochemical reactor entering unit C through line (9) in a halogenated product stream containing mainly mono- and dihalogenated carbonyl derivatives leaving the device of the invention through the outlet (11).

In another embodiment, the device comprises an additional separation unit (D) for separating monohalogenated compounds from the corresponding di or more halogenated compounds. This device is shown in FIG. 2.

In more detail, according to FIG. 2, in the apparatus of this embodiment, the product from the chemical reactor (A) is introduced into the physical separation unit (C) via line (5) as described above to separate the electrolyte and other components or products formed in the chemical reactor A from the mono mixture -, di- and / or more halogenated carbonyl products transferred to the separation unit D via line (12).

Separation unit D contains separation means capable of separating monohalogenated compounds from the corresponding di- and more halogenated compounds. These separation means may be distillation columns, crystallization units, extraction unit, or any combination thereof to obtain the desired separation. Unit D produces a purified monohalogenated product discharged via line (14) and a stream substantially enriched with di- and / or more halogenated product, which is introduced into the electrochemical reactor (B) described above through inlet (13).

In the apparatus of the embodiment shown in FIG. 2, the product from the electrochemical reactor (B), substantially enriched with the monohalogenated product, can be introduced into the chemical reactor (A) via line (15). Additionally, a stream containing electrolyte and other components from the physical separation unit (C) is introduced into the electrochemical reactor (B) and / or chemical reactor (A) via line (10). Optionally, a stream containing a halide (gas or liquid) and a stream including compounds containing a carbonyl group can be introduced into the electrochemical installation (B) also through the input lines (7) and (2), respectively, which can be combined into one input line . In the electrochemical reactor (B), hydrogen gas can be generated at the cathode and removed from the reactor via line (8).

In a preferred embodiment, the method of the invention is implemented essentially in the absence of a solvent. By the term “substantially in the absence of solvent” is meant that at most 5% of the solvent is present in the reaction mixture. The term "solvent" is intended to encompass any substance in which at least the starting materials of the reaction are soluble but do not include any reagents / products. More preferably, in the method of the invention, the reaction mixture contains less than 2% solvent. Most preferably, about 0% solvent is present.

It is understood that the resulting chemical reactions in the process of the invention are

H-X + R-COY-> XR-COY + H ₂

R'-X + R-COY-> X-R-COY + R'-H or

MX _n + n R-COOH -> (XR-COO) _n M + nH ₂

The carbonyl group-containing compound R-COY or R-COOH to be halogenated may be any compound containing a hydrogen atom of α-carbon, preferably liquid at the reaction temperature. The carbonyl group-containing compound R-COY may be an aldehyde, a ketone, a carboxylic acid, a carboxylic anhydride or an acyl halide. Preferably, R-COY and R-COOH are carbonyl group-containing compounds in which R is an alkyl, alkylene or aryl group containing α-hydrogen atoms, which may be linear, cyclic or branched, possibly containing one or more heteroatoms, such as oxygen , nitrogen, chloride, bromide or iodide, and Y is hydrogen, a hydroxyl group, a halogen atom or an R "or OCOR" group, each R "independently is a hydrogen atom or an alkyl, alkylene or aryl group. More preferably, Y is a hydroxyl group, a halogen atom, an R "or OCOR" group, wherein R "is a C ₁ -C ₁₀ alkyl or C ₁ -C ₁₀ alkylene group, and R is a C ₁ -C ₂₆ alkyl or C ₁ -C ₂₆ alkylene group. Even more preferably, the carbonyl group-containing compound is an unsubstituted C ₂ -C ₂₆ carboxylic acid, even more preferably acetic acid, propionic acid or a fatty acid, most preferably acetic acid. Fatty acid is defined as a carboxylic acid with hydrocarbyl groups containing 1-22 carbon atoms, preferably 8-22 carbon atoms, which may be saturated or unsaturated, linear or branched. It is assumed that fatty acids derived from natural fats and oils contain at least 8 carbon atoms. Preferred fatty acids of the present invention are unbranched C ₈ -C ₂₆ carboxylic acids, even more preferred is a group of natural fatty acids, as described, for example, in CRC Handbook of Chemistry and Physics , 1989 ed., D-220.

The halide is chloride, bromide or iodide, more preferably chloride or bromide, most preferably chloride.

Organic halide R'-X may be any compound that can be dehalogenated in the electrochemical stage, such as, for example, disclosed in Lund, Hammerich, Organic Electrochemistry , 4th ed., Chapter 8, "Halogenated organic compounds" (Marcel Dekker, 2001). R'-X is preferably a halogenated hydrocarbon compound, which may further contain substituents, such as nitrogen or oxygen. Most preferably, R'-X is a di- and / or more halogenated compound containing a carbonyl group.

The halide salt of M ^{n +} -X _{n is} preferably a halide salt in which M is a cation of an alkaline earth metal, alkali metal or metal, more preferably M is a cation of Na, K, Li, Mg, Ca, Ba, even more preferably an alkali metal cation, most preferably a lithium, sodium or potassium cation.

In an even more preferred embodiment, the reaction mixture contains mainly only reagents, products and excipients, i.e. more than 95% by weight of the reaction mixture is comprised of starting materials, products and excipients, and most preferably it contains more than 99% by weight of these components. Excipients are defined as agents that can act in the process of the invention, such as a catalyst and a supporting electrolyte.

In principle, a supporting electrolyte is not necessary in the process, provided that sufficient current can pass through the liquid under the process conditions. In a preferred embodiment, a support electrolyte is present in the reaction mixture. This electrolyte is a non-aqueous compound (a mixture of such compounds), which is sufficiently soluble and provides sufficient conductivity in the reaction mixture used, can be easily separated and recycled and is sufficiently stable to oxidation and reduction. Examples of such supporting electrolytes can be any combination of ions indicated, for example, in F. Beck, Elektroorganische Chemie , Verlag Chemie GmbH, Weinheim, 1974, Chapter 3.3, pp. 104-110, or in D. Pletcher, A First Course in Electrode Processes , The Electrochemical Consultancy , Alresford Press Ltd., 1991, Chapter 2,3, pp. 57-72, and may include ions such as OH ^- , I ^- , Br ^- , Cl ^- , F ^- , NO ₃ ^- , SO ₄ ^2- , HCO ^3- , Fe (CN) ₆ ^3- , ClO ₄ ^- , BF ₄ ^- , PF ₆ ^- , H ⁺ , Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Ca ²⁺ , Mg ²⁺ , Al ³⁺ , La ³⁺ , Ag ⁺ , NH ₄ ⁺ , [N ( CH ₃ ) ₄ ] ⁺ , [N (C ₂ H ₅ ) ₄ ] ⁺ , [N (C ₄ H ₉ ) ₄ ] ⁺ , [N (C ₂ H ₅ ) H] ⁺ . More preferably, the electrolyte is a salt soluble in the halogenated carboxylic acid and either not participating in the halogenation reaction or participating, but in this case containing the same halogen source as the starting halogen in the reaction, to prevent the formation of other halogenated compounds containing carbonyl a group. In an even more preferred embodiment, the electrolyte is a halide salt such as NaCl, NaBr, NaI, KCl, KBr, KI, LiCl, LiBr, LiI, MgCl ₂ , MgBr ₂ , MgI ₂ , CaCl ₂ , CaBr ₂ , CaI ₂ , BaCl ₂ , BaBr ₂ , BaI ₂ . In a most preferred embodiment, the metal salt MX _n acts as a supporting electrolyte.

In another preferred embodiment, a reaction accelerating compound (also referred to as a catalyst) is present in the reaction mixture. In a more preferred embodiment, the compound is a halogenated carboxylic acid (derivative) anhydride or its halide. In an embodiment comprising a two-step process, i.e. a chemical halogenation step followed by an electrochemical step, the aforementioned acid halide catalyst can be formed in the reaction mixture (i.e. it does not need to be added) when products such as PCl ₃ or SOCl ₂ or SO ₂ Cl ₂ , COCl ₂ , anhydride are used in the chemical stage acid or sulfur (as a catalyst). As already briefly noted above, these types of acid anhydrides and acid halides have the additional advantage that they bind water to give carboxylic acid and are thus able to make the reaction conditions completely anhydrous. The catalyst is used in conventional amounts from 2 to 30% by weight of the total reaction mixture.

An additional advantage of the method according to the invention is that, since the electrochemical reaction is carried out in a non-aqueous medium, the catalytic compound does not decompose under the action of water present in the reaction mixture.

The electrodes used can be selected from any material, unless it is destroyed in the reaction mixture under the reaction conditions to form undesirable by-products. In this regard, the choice of anode material is especially important, since the anode is most sensitive to degradation under process conditions. In a preferred embodiment, the anode is made of carbon (such as boron-doped diamond, graphite, glassy carbon), ceramic (such as magnetite, i.e. Fe ₃ O ₄ or Ebonex®, i.e. mixed titanium oxides), a metal alloy ( such as platinum / ruthenium) or a noble metal (such as Au, Ag, Pd, Pt, Ti), possibly containing a mixed metal oxide, such as IrO ₂ / RuO ₂ (for example, IrO ₂ / RuO ₂ on titanium, non-consumable anodes - Dimension Stable Anodes: DSA® electrodes), and the cathode is made of carbon (such as boron-doped diamond, graphite, glassy carbon), metals (that such as nickel, lead, mercury, titanium, iron, chromium), a metal alloy (such as stainless steel (Cr-Ni-Fe), monel (Cu-Ni), brass (Cu-Zn), or metal oxides (such as Pb / PbO ₂ ), or it can be any other electrode as long as it is stable in the system and does not form significant quantities of unwanted by-products. Examples of electrode materials are mentioned in AJ Bard, M. Stratmann, Eds., Encyclopedia of Electrochemistry, Organic Electrochem. , Vol. 8, Chapter 2,4.1, p. 39 to which reference is made.

In addition, in the method according to the invention, the electrodes are preferably selected so that their specific surface is as large as possible and so that the distance between the cathode and the anode is as small as possible. A person skilled in the art will not have any problems in selecting electrodes suitable for this purpose. As non-limiting examples of electrodes that satisfy one or more of the above criteria, concentric electrodes, porous electrodes, parallel plate electrodes, dispersed electrodes, fluidized electrodes can be mentioned. The arrangement of the electrodes may be unipolar or bipolar.

The electric current density in the process according to the invention is usually from 0.1 to 7 kA / m ² , preferably from 0.5 to 4 kA / m ² and most preferably from 1 to 2 kA / m ² . The voltage between the electrodes in the electrolyzer typically ranges from 1 to 10 volts, depending mainly, but not exclusively, on the applied current density, conductivity of the reaction medium and the distance between the electrodes.

The method of the invention can be combined with a UV treatment step, in which gaseous halogen is added to the reaction system and converted to a halogen atom by UV irradiation and also becomes capable of reacting with a compound containing a carbonyl group to obtain the desired halogenated compound containing a carbonyl group.

The method according to the invention can be carried out in batch, semi-batch or continuous modes, preferably, it is a continuous process.

The method can be carried out at a pressure that is usually in the range from 1 to 10 bar abs., Preferably, the pressure is from 0.9 to 5 bar abs., Most preferably about 1-2 bar abs. Bar abs. means absolute pressure in bars.

The method is usually carried out at a temperature of from 11 to 200 ° C, preferably from 20 to 150 ° C, more preferably from 75 to 140 ° C, most preferably from 80 to 120 ° C.

The invention is further illustrated by the following examples and comparative examples.

Examples

Example 1: Chlorination of Acetic Acid Using HCl

In a reactor containing graphite anodes and cathodes (material type 6503, Le Carbonne Lorraine, Rotterdam, the Netherlands) with an effective anode area of 580 cm ² and an effective cathode area of 530 cm ² 800 grams of a mixture containing 7 wt.% Anhydrous calcium chloride (JT. Baker, No. 0070, min. 95% by weight), 69% of acetic acid (Fluka, No. 45731,> 99.8% by weight), and 24% by weight of acetyl chloride (Fluka, No. 00990,> 99%) were preheated up to 70 ° C and subjected to electrolysis at an average current of 20 amperes. During electrolysis, gaseous hydrogen chloride was added to the reaction mixture.

Samples taken from the electrolyte during electrolysis were analyzed by high performance liquid chromatography (HPLC).

Table 1 shows the concentrations of monochloracetic acid (MCA) and dichloroacetic acid (DCA), measured by HPLC (in wt.% Of the total amount of acetic acid (HAc), MCA and DCA), depending on the amount of electric charge transferred during the process.

Table 1
The concentration of monochloracetic acid (MCA) and dichloroacetic acid (DCA) of the amount of electric charge transferred during the electrolysis of the mixture, which initially contains acetic acid, acetyl chloride, calcium chloride and hydrogen chloride (Example 1) Try Transferred charge (Ah) MCA content {wt.%} DCA content {wt.%} one 5 0.6 0.003 2 16 2.6 0.007 3 34 7.1 0.013 four 51 10.7 0,020 5 59 12.3 0.024 6 78 16.1 0,029 7 107 21.6 0,044 8 140 27.4 0,054

Example 2 : Chlorination of acetic acid using CaCl ₂ (in the absence of HCl)

In the reactor as mentioned in Example 1, 650 grams of a mixture of 72 wt.% Acetic acid (Fluka, No. 45731,> 99.8 wt.%), 21 wt.% Acetyl chloride (Fluka, No. 00990,> 99%) and 7 wt.% anhydrous calcium chloride (JT. Baker, No. 0070, min. 95 wt.%) was preheated to 70 ° C and subjected to electrolysis at an electric current of 5 to 20 amperes. Unlike Example 1, in the present example, gaseous hydrogen chloride was not added to the reaction mixture.

Samples taken from the electrolyte during electrolysis were analyzed by high performance liquid chromatography (HPLC).

Analysis results show that MCA can be obtained from this mixture even in the absence of hydrogen chloride.

Table 2 shows the concentrations of monochloracetic acid (MCA) and dichloroacetic acid (DCA), measured by HPLC (in wt.% Of the total amount of acetic acid (HAc), MCA and DCA) depending on the amount of electric charge transferred during the process.

table 2
The concentration of monochloracetic acid (MCA) and dichloroacetic acid (DCA) of the amount of electric charge transferred during the electrolysis of the mixture, which initially contains acetic acid, acetyl chloride and calcium chloride (Example 2) Try Transferred charge (Ah) MCA content {wt.%} DCA content {wt.%} one 0.5 0.6 0.003 2 2.6 1.4 0.007 3 7.3 2.7 0.010 four 12.5 4.1 0.018 5 16.8 5,0 0.019 6 26.6 7.6 0,026

Example 3: Chlorination of Acetic Acid Using Dichloroacetic Acid

In the reactor, which is mentioned in Example 1, 700 grams of a mixture of 60 wt.% Acetic acid (Fluka, No. 45731,> 99.8 wt.%), 19 wt.% Acetyl chloride (Fluka, No. 00990,> 99%), 5 wt.% anhydrous calcium chloride (JT. Baker, No. 0070, min. 95 wt.%) and 16 wt.% dichloroacetic acid (Acros Chemicals, batch A0220473, 99 +%) were pre-heated to 70 ° C and subjected to electrolysis by electric current of 20 amperes. Hydrogen chloride gas was added to the reaction mixture.

Samples taken from the electrolyte during electrolysis were analyzed by high performance liquid chromatography (HPLC).

The analysis results show that, compared with Example 2, the rate of MCA in the present example is almost two times higher. Acetic acid is chlorinated, and DCA is hydrogenated to MCA.

Table 3 shows the concentrations of monochloracetic acid (MCA) and dichloroacetic acid (DCA), measured by HPLC (in wt.% Relative to the total amount of acetic acid (HAc), MCA and DCA), depending on the amount of electric charge transferred during the process.

Table 3
Concentrations of acetic acid (HAc), monochloroacetic acid (MCA) and dichloroacetic acid (DCA) from the amount of electric charge transferred during the electrolysis of the mixture, which initially contains acetic acid, acetyl chloride, monochloracetic acid, dichloroacetic acid and calcium chloride (Example 3) Try Transferred charge (Ah) HAc content {wt.%} MCA content {wt.%} DCA content {wt.%} one 0,0 80,4 2.0 17.6 2 28 74,2 12.1 13.7 3 60 68.1 22.7 9.2 four 95 61.7 33.3 5,0 5 123 57.2 40.1 2.6 6 140 54.8 43.5 1.7

Example 4 : Chlorination of Propionic Acid Using HCl

In the reactor, as mentioned in Example 1, 840 grams of a mixture of 65 wt.% Propionic acid (Fluka, lot no. 1241470,> 99 wt.%), 30 wt.% Propionic anhydride (Aldrich, lot No. 05003 HC-026, 97% ) and 5 wt.% anhydrous calcium chloride (JT. Baker, No. 0070, min. 95 wt.%) were preheated to 70 ° C and subjected to electrolysis at an electric current of 1 to 9 amperes. During electrolysis, gaseous hydrogen chloride was added to the reaction mixture.

Samples taken from the electrolyte during electrolysis were analyzed by high performance liquid chromatography (HPLC).

The analysis results show that 1-chloropropionic acid can be obtained from the mixture.

Table 4 shows the concentrations of propionic acid and 1-chloropropionic acid measured by HPLC (in wt.% Of the total amount of propionic acid and 1-chloropropionic acid), depending on the amount of electric charge transferred during the process.

Table 4
The concentration of propionic acid and 1-chloropropionic acid on the amount of electric charge transferred during the electrolysis of the mixture, which initially contains propionic acid, propionic anhydride and calcium chloride (Example 4) Try Transferred charge (Ah) The content of propionic acid {wt.%} 1-chloropropionic acid [wt.%] one 0,0 99.9 0.1 2 0.1 100.0 0,0 3 0.9 99.8 0.2 four 2.2 99.5 0.5 5 5.3 98.8 1,2 6 8.2 98.2 1.8 7 11.8 97.1 2.9 8 15.3 96.6 3.4 9 19,4 95.6 4.4 10 24.1 94.6 5,4 eleven 29.9 93,4 6.6 12 37.3 91.3 8.7

Comparative Example 5: Chlorination of acetic acid in an aqueous medium

In a 1 liter beaker, a mixture containing 500 ml of hydrochloric acid (10 wt.% HCl in water) was charged and electrolyzed at room temperature at a current of 2 amperes to give chlorine gas. After two hours of electrolysis, 150 ml of acetic acid (70% by weight) was added to the reaction mixture and electrolyzed for another 1.5 hours at 2 amperes at room temperature.

Samples taken during the process were evaluated by ¹ H-NMR. Using NMR, only trace amounts of MCA could be detected, the amount of DCA was below the detection limit (the detection limit of MCA and DCA for this NMR instrument is about 50 ppm).

Example 6 : Obtaining bromoacetic acid using LiBr

In a reactor containing graphite anodes and cathodes (material type 6503 Le Carbonne Lorraine, Rotterdam, Netherlands) with an effective anode area of 580 cm ² and an effective cathode area of 530 cm ² , 900 grams of a mixture containing 11% anhydrous lithium bromide, 33% acetyl bromide and 56% acetic acid (Fluka No. 00990,> 99%) was preheated to 70 ° C and electrolyzed at an average current of 20 amperes. Samples taken from the electrolyte during electrolysis were analyzed by high performance liquid chromatography (HPLC). After passing through the electrodes of a charge of 83 Ah, 12.97% of bromoacetic acid and 0.017% of dibromoacetic acid were formed.

Example 7: Chlorination of Acetic Acid Using HCl and Sodium Chloride as an Electrolyte

In a reactor containing graphite anodes and cathodes (material type 6503 Le Carbonne Lorraine, Rotterdam, the Netherlands) with an effective anode area of 580 cm ² and an effective cathode area of 530 cm ² , 808 grams of a mixture containing 11% anhydrous sodium chloride, 33% acetic anhydride and 56% acetic acid (Fluka no. 00990,> 99%) was preheated to 70 ° C and electrolyzed at an average current of 3.8 amperes. During electrolysis, gaseous hydrogen chloride was added to the reaction mixture. Samples taken from the electrolyte during electrolysis were analyzed by high performance liquid chromatography (HPLC). After passing through the charge electrodes 15.9 Ah, 3.66% MCA and 0.043% DCA are formed.

Example 8: Chlorination of acetic acid using HCl and lithium chloride as an electrolyte

In a reactor containing graphite anodes and cathodes (material type 6503 Le Carbonne Lorraine, Rotterdam, the Netherlands) with an effective anode area of 580 cm ² and an effective cathode area of 530 cm ² , 808 grams of a mixture containing 1.3% anhydrous lithium chloride, 6, 6% acetyl chloride and 92.1% acetic acid (Fluka No. 00990,> 99%) were preheated to 70 ° C and electrolyzed at an average current of 20 amperes. During electrolysis, gaseous hydrogen chloride was added to the reaction mixture. Samples taken from the electrolyte during electrolysis were analyzed by high performance liquid chromatography (HPLC). After passing 112 A · h of charge through the electrodes, 22.76% MCA and 0.108% DCA are formed.

Example 9 : Chlorination of acetic acid using HCl and potassium chloride as an electrolyte

In a reactor containing graphite anodes and cathodes (material type 6503 Le Carbonne Lorraine, Rotterdam, Netherlands) with an effective anode area of 580 cm ² and an effective cathode area of 530 cm ² , 808 grams of a mixture containing 10% anhydrous potassium chloride, 24% acetyl chloride and 66% of acetic acid (Fluka No. 00990,> 99%) was preheated to 70 ° C and electrolyzed at an average current of 10 amperes. During electrolysis, gaseous hydrogen chloride was added to the reaction mixture. Samples taken from the electrolyte during electrolysis were analyzed by high performance liquid chromatography (HPLC). After passing through the charge electrodes 57.7 Ah, 13.39% MCA and 0.57% DCA are formed.

Example 10 : Chlorination of acetic acid using trichloroacetic acid and HCl.

In a reactor containing graphite anodes and cathodes (material type 6503 Le Carbonne Lorraine, Rotterdam, the Netherlands) with an effective anode area of 580 cm ² and an effective cathode area of 530 cm ² , 808 grams of a mixture containing 11.9% trichloroacetic acid (TCA), 4.8% anhydrous lithium chloride, 11.9% acetyl chloride and 71.4% acetic acid (Fluka No. 00990,> 99%) were preheated to 70 ° C and subjected to electrolysis at an average current of 30 amperes. During electrolysis, gaseous hydrogen chloride was added to the reaction mixture. Samples taken from the electrolyte during electrolysis were analyzed by high performance liquid chromatography (HPLC).

The results in Table 5 show that at the end of the process, both DCA and TCA decreased and MCA increased.

Table 5
The concentrations of monochloracetic acid (MCA), dichloroacetic acid (DCA) and trifluoroacetic acid (TCA) from Example 10, measured by HPLC (in wt.% Of the total amount of acetic acid (Hac), MCA, TCA and DCA), depending on the amount electric charge transferred during the process Ah MCA Content (%) DCA Content (%) TCA Content (%) 0 0.13 0.00 13.32 16 3.69 2.85 9.47 30.5 7.34 5.13 5.99 47.5 11.69 6.51 3.18 63.5 16.04 6.82 1.51 86 22.00 5.96 0.42 118.5 30.00 3.96 0.05 135.5 33.96 3.01 0.02 152 37.33 2.19 0.01 170 40.51 1,50 0.00 186 43.33 1.06 0.00 211.5 47.18 0.63 0.00

Example 11 : Recovery of the mother liquor with lithium chloride as an electrolyte (Chlorination of acetic acid using dichloroacetic acid and HCl)

In a reactor containing graphite anodes and cathodes (material type 6503 Le Carbonne Lorraine, Rotterdam, the Netherlands) with an effective anode area of 580 cm ² and an effective cathode area of 530 cm ² , 1007 grams of a mixture containing 30% dichloroacetic acid (DCA), 5% anhydrous lithium chloride, 15% acetyl chloride, 30% monochloracetic acid (MCA) and 20% acetic acid (Fluka No. 00990,> 99%) were preheated to 70 ° C and subjected to electrolysis at an average current of 30 amperes. During electrolysis, gaseous hydrogen chloride was added to the reaction mixture.

Samples taken from the electrolyte during electrolysis were analyzed by high performance liquid chromatography (HPLC). The results in Table 6 show that at the end of the process, both the Hac and DCA content decreased, and the MCA content increased.

Table 6
Concentrations of monochloracetic acid (MCA), dichloroacetic acid (DCA) and acetic acid (HAc) from Example 11, measured by HPLC (in wt.% Of the total amount of HAc, MCA and DCA), depending on the amount of electric charge transferred during the process Ah MCA Content (%) DCA Content (%) HAc content (%) 0 32.34 32,48 35.18 208 75.33 8.34 16.33

Example 12 : Recovery of a mother liquor with calcium chloride as an electrolyte (Chlorination of acetic acid using dichloroacetic acid and HCl)

In a reactor containing graphite anodes and cathodes (material type 6503 Le Carbonne Lorraine, Rotterdam, the Netherlands) with an effective anode area of 580 cm ² and an effective cathode area of 530 cm ² , 1007 grams of a mixture containing 30% dichloroacetic acid (DCA), 5% anhydrous calcium chloride, 15% acetyl chloride, 30% monochloracetic acid (MCA) and 20% acetic acid (Fluka No. 00990,> 99%) were preheated to 70 ° C and subjected to electrolysis at an average current of 30 amperes. During electrolysis, gaseous hydrogen chloride was added to the reaction mixture.

Samples taken from the electrolyte during electrolysis were analyzed by high performance liquid chromatography (HPLC). The results in Table 7 show that at the end of the process, both the Hac and DCA content decreased, and the MCA content increased.

Table 7
The concentration of monochloracetic acid (MCA), dichloroacetic acid (DCA) and acetic acid (HAc) from Example 12, measured by HPLC (in wt.% In relation to the total amount of HAc, MCA, and DCA), depending on the amount of electric charge, transferred during the process Ah MCA Content (%) DCA Content (%) HAc content (%) 0 32.08 32.17 35.75 216 71.63 10.76 17.25

Example 13 : Recovery of a mother liquor with magnesium chloride as an electrolyte (Chlorination of acetic acid using dichloroacetic acid and HCl)

In a reactor containing graphite anodes and cathodes (material type 6503 Le Carbonne Lorraine, Rotterdam, Netherlands) with an effective anode area of 580 cm ² and an effective cathode area of 530 cm ² , 1007 grams of a mixture containing 30% dichloroacetic acid (DCA), 5, 2% anhydrous magnesium chloride, 15% acetyl chloride, 30% monochloracetic acid (MCA), and 20% acetic acid (Fluka No. 00990,> 99%) were preheated to 70 ° C and electrolyzed at an average current of 30 amperes. During electrolysis, gaseous hydrogen chloride was added to the reaction mixture. Samples taken from the electrolyte during electrolysis were analyzed by high performance liquid chromatography (HPLC). The results in Table 8 show that at the end of the process, the content of both Hac and DCA decreases, while the content of MCA increases.

Table 8
The concentration of monochloracetic acid (MCA), dichloroacetic acid (DCA) and acetic acid (HAc) from Example 13, measured by HPLC (in% of the total weight quantity of HAc, MCA, and DCA) depending on the amount of electric charge transferred during the process . Ah MCA Content (%) DCA Content (%) HAc content (%) 0 32.67 32.76 34.57 186 67.32 11.34 18.28

Example 14: Chlorination of Acetic Acid Using HCl and Zinc Chloride as an Electrolyte

In a reactor containing graphite anodes and cathodes (material type 6503 Le Carbonne Lorraine, Rotterdam, Netherlands) with an effective anode area of 580 cm ² and an effective cathode area of 530 cm ² , 1607 grams of a mixture containing 5% anhydrous zinc chloride, 13% acetyl chloride and 82% of acetic acid (Fluka No. 00990,> 99%) was preheated to 70 ° C and electrolyzed at an average current of 25 amperes. During electrolysis, gaseous hydrogen chloride was added to the reaction mixture. Samples taken from the electrolyte during electrolysis were analyzed by high performance liquid chromatography (HPLC). After passing through the electrodes of a charge of 162 Ah, 15.67% MCA and 0.10% DCA are formed.

Example 15: Chlorination of Acetic Acid with Iron (III) Chloride as an Electrolyte

In a reactor containing graphite anodes and cathodes (material type 6503 Le Carbonne Lorraine, Rotterdam, Netherlands) with an effective anode area of 580 cm ² and an effective cathode area of 530 cm ² , 1607 grams of a mixture containing 5% anhydrous iron (III) chloride, 13 % acetyl chloride and 82% acetic acid (Fluka No. 00990,> 99%) were preheated to 70 ° C and electrolyzed at an average current of 30 amperes. During electrolysis, gaseous hydrogen chloride was added to the reaction mixture. Samples taken from the electrolyte during electrolysis were analyzed by high performance liquid chromatography (HPLC). After passing through the electrodes of the charge 192 A · h, 4.73% MCA and 0.10% DCA are formed.

Example 16: Chlorination of acetic acid using HCl and aluminum chloride as an electrolyte

In a reactor containing graphite anodes and cathodes (material type 6503 Le Carbonne Lorraine, Rotterdam, the Netherlands) with an effective anode area of 580 cm ² and an effective cathode area of 530 cm ² , 1607 grams of a mixture containing 5% anhydrous aluminum chloride, 13% acetyl chloride and 82% of acetic acid (Fluka, No. 00990,> 99%) was preheated to 70 ° C and electrolyzed at an average current of 30 amperes. During electrolysis, gaseous hydrogen chloride was added to the reaction mixture. Samples taken from the electrolyte during electrolysis were analyzed by high performance liquid chromatography (HPLC). After passing through the electrodes of the charge 119 A · h, 12.29% MCA and 0.02% DCA are formed.

Example 17: Chlorination of dimethylpentanone using HCl

In a reactor containing graphite anodes and cathodes (material type 6503 Le Carbonne Lorraine, Rotterdam, Netherlands) with an effective anode area of 47 cm ² and an effective cathode area of 16 cm ² , 61 grams of a mixture containing 6% anhydrous lithium chloride, 94% 2, 4-dimethylpentanone was preheated to 70 ° C and electrolyzed at an average current of 0.3 amperes. During electrolysis, gaseous hydrogen chloride was added to the reaction mixture. Samples taken from the electrolyte during electrolysis were analyzed by NMR.

The results in Table 9 show that 2-chloro-2,4-dimethylpentanone is formed at the end of the process.

Table 9
The concentration (in mol%) of 2,4-dimethylpentanone and 2-chloro-2,4-dimethylpentanone from Example 17, measured by NMR Ah 2,4-dimethylpentanone 2-chloro-2,4-dimethylpentanone 0 one hundred 0.00 6 98.5 1,5

Comparative Example 18 : Fluorination of acetic acid using trifluoroacetic acid (TFA)

In a reactor containing graphite anodes and cathodes (material type 6503 Le Carbonne Lorraine, Rotterdam, Netherlands) with an effective anode area of 47 cm ² and an effective cathode area of 16 cm ² , 99 grams of a mixture containing 4% anhydrous lithium chloride, 35.4% TFA, 35.4% acetic acid and 25.2% acetyl chloride were preheated to 70 ° C and electrolyzed at an average current of 2 amperes. Samples taken from the electrolyte during electrolysis were analyzed by NMR. No evidence was found in the samples to form monofluoroacetic acid or difluoroacetic acid. Only MCA and small amounts of DCA were detected.

Comparative Example 19 : Fluorination of Acetic Acid Using KF

In a reactor containing graphite anodes and cathodes (material type 6503 Le Carbonne Lorraine, Rotterdam, Netherlands) with an effective anode area of 47 cm ² and an effective cathode area of 16 cm ² , 99 grams of a mixture containing 4.3% anhydrous potassium fluoride, 68, 5% acetic acid and 27.2% acetyl chloride were preheated to 70 ° C and electrolyzed at an average current of 0.4 amperes. Samples taken from the electrolyte during electrolysis were analyzed by NMR. No evidence was found in the samples of the formation of monofluoroacetic acid or difluoroacetic acid. Only MCA and small amounts of DCA were detected.

Example 20: Chlorination of dodecanoic acid using HCl and LiCl as an electrolyte

In a reactor containing graphite anodes and cathodes (material type 6503 Le Carbonne Lorraine, Rotterdam, the Netherlands) with an effective anode area of 47 cm ² and an effective cathode area of 16 cm ² , 92 grams of a mixture containing 4.9% anhydrous lithium chloride, 35, 3% acetic acid, 35.3% dodecanoic acid and 24.5% acetyl chloride, were preheated to 70 ° C and subjected to electrolysis at an average current of 1 ampere. Samples taken from the electrolyte during electrolysis were analyzed by NMR. After passing through the electrodes of the charge 3.4 A · h, 1.3 mol% of 2-chloro-dodecanoic acid is formed.

Example 21 : Chlorination of Octodecanoic Acid Using HCl

In a reactor containing graphite anodes and cathodes (material type 6503 Le Carbonne Lorraine, Rotterdam, the Netherlands) with an effective anode area of 47 cm ² and an effective cathode area of 16 cm ² , 92 grams of a mixture containing 4.7% anhydrous lithium chloride, 38, 3% acetic acid, 33.6% octodecanoic acid and 23.4% acetyl chloride were preheated to 70 ° C and electrolyzed at an average current of 1 ampere. Samples taken from the electrolyte during electrolysis were analyzed by NMR. After passing through the electrodes of the charge 3.2 A · h, 1.3 mol% of 2-chloro-octodecanoic acid is formed.

Claims (13)

1. A method of obtaining a halogenated compound containing a carbonyl group by electrochemical reaction of the corresponding compound containing a carbonyl group with a hydrogen halide HX, an organic halide R′X and / or a halide salt M ^{n +} —X _n ^″ in essentially anhydrous conditions, wherein X is a chlorine, bromine or iodine atom, R 'is an alkyl or aryl group which may be linear or branched, optionally containing one or more heteroatoms, such as oxygen, nitrogen; chloride, bromide, fluoride or iodide, from which the halogen atom X can be eliminated electrochemically, M ^{n +} means a quaternary ammonium cation, alkaline earth metal, alkali metal or metal, and n is an integer from 1 to 5 depending on the valency of the metal cation M ^{n +} . 2. The method according to claim 1, wherein the organic halide R′-X is twice and / or more halogenated compound containing a carbonyl group. 3. The method according to claim 1 or 2, wherein the obtained halogenated compound containing a carbonyl group is a monohalogenated compound. 4. The method according to any one of claims 1 to 2, wherein the resulting halogenated compound containing a carbonyl group is halogenated at the 6-carbon atom. 5. A method of obtaining a halogenated compound containing a carbonyl group, first by chemical reaction of a compound containing a carbonyl group with chlorine, bromine or iodine molecules and subsequent electrochemical treatment of the reaction mixture in accordance with the method according to claim 1. 6. A method of obtaining a halogenated compound containing a carbonyl group, in which the mother liquor obtained by monohalogenation of a compound containing a carbonyl group is separated from the reaction mixture containing both a monohalogenated compound with a carbonyl group and a di- and / or more halogenated compound containing a carbonyl group is used in a method comprising the electrochemical reaction of a corresponding compound containing a carbonyl group with a di- and / or more halogenated compound optionally containing a carbonyl group, an H-X hydrohalide, an additional organic halide R′-X and / or a halide salt M ^{n +} -X _n ^″ under substantially anhydrous conditions, wherein X represents a chlorine, bromine or iodine atom , R 'is an alkyl or aryl group which may be linear or branched, optionally containing one or more heteroatoms from which the halogen atom X can be removed electrochemically, M ^{n +} is a quaternary ammonium or metal cation, and n is an integer from 1 to 5 depending on valence STI metal cation M ^{n +.} 7. The method according to claim 6, in which an additional compound containing a carbonyl group is added. 8. The method according to any one of claims 1, 2, 5, 6, or 7, wherein X represents a chlorine atom. 9. The method according to any one of claims 1, 2, 5, 6, or 7, wherein the compound containing a carbonyl group is acetic acid, or propionic acid, or a fatty acid. 10. The method according to claim 1, in which the reaction mixture additionally contains a supporting electrolyte. 11. The method according to any one of claims 1, 2, 5, 6, 7, or 10, wherein the supporting electrolyte is a chlorine salt. 12. The method according to any one of claims 1, 2, 5, 6, 7 or 10, moreover, a catalyst selected from the group of acyl halides and carboxylic anhydrides is added to the reaction mixture. 13. The method according to any one of claims 1, 2, 5, 6, 7, or 10, carried out essentially in the absence of any solvents.

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