DE1926852A1 - Process for the chlorination of organic compounds - Google Patents

Description

Process for the chlorination of organic compounds The invention relates to a process for the chlorination of organic compounds using of copper (II) chloride.

Copper (II) chloride is used as a chlorinating agent for the chlorination of organic compounds and has so far been i.a.

for the chlorination of ketones, aldehydes, aliphatic carboxylic acids, reactive aromatic hydrocarbons, olefins and phenols in the liquid phase used.

It has been found that chlorination is more organic links with copper (II) chloride is more specific than the chlorination of the same organic Compounds with molecular chlorine or other chlorinating agents, since the chlorine atom is preferably linked to the substrate molecule at a certain position. For example, copper (II) chloride became the aliphatic chlorinating agent Carboxylic acids used.

These acids are only chlorinated in the a-position.

In the case of phenols, the chlorination takes place in a similar manner largely in the p-position.

Another significant advantage of using copper (II) chloride as the chlorinating agent is the ease with which the reaction product, and Although copper (I) chloride can still be converted into copper (II) chloride, by treatment with air and hydrochloric acid. In one of those Therefore, hydrochloric acid acts as a chlorinating agent.

The main disadvantage of using cupric chloride as a chlorinating agent is that the rate of chlorination of organic substrates is low is, with this speed in many cases for an implementation in tech nical standard is not sufficient. In particular, it was found that the Chlorination reaction produced copper (I) chloride seriously the chlorination inhibits, this is possibly due to the fact that copper (I) chloride is a forms a relatively stable complex with the unreacted copper (II) chloride, so that this latter compound is no longer available for a further reaction stands.

The aim of the invention is to increase the rate of chlorination reactions using copper (II) chloride as the chlorinating agent and reducing it the disadvantages previously encountered with the use of copper (II) chloride as a chlorinating agent Instruct, to a minimum.

The invention provides a method for the chlorination of organic Compounds for filming made, which be in it, one or more organic Compounds with copper (II) chloride in the presence of at least one other metal chloride or oxychloride with the exception of alkali or alkaline earth chlorides and to separate off the chlorinated products formed.

Preferably the chlorination reaction is carried out using a Reactant solution carried out.

In general, these are those used according to the invention Metal chlorides and oxychlorides around compounds of elements 21 - 28 (including) as well as the elements 57 - 71 (including) of the Periodic Table of the Elements. There are preferably those used to carry out the method according to the invention additional metal chlorides from aluminum chloride, vanadyl chloride and chromium (III) -chlorld or mixtures of these metal chlorides. In general, the metal chloride will be used. However, if this is quickly hydrolyzed to an oxychloride in water, then the metal oxychloride can be used in place of the metal chloride.

It should be pointed out that at least some of the of the metal chloride or oxychloride of the reaction mixture after initiation can be added to the chlorination reaction. In some cases it can be useful be all of the metal chloride or oxychloride after initiation of the chlorination reaction to add. If this procedure is adhered to, there is generally a considerable amount Part of the chlorination reaction in the presence of the metal chloride or oxychloride carried out.

Because of the increase in the rate of the chlorination reactions in the presence of the metal chlorides specified above, the temperature can be which the chlorination reaction is carried out is reduced in many cases will. In this way the formation of undesired by-products is often reduced, in addition, the need to work at above atmospheric pressure can be dispensed with. Consequently, the products that are used when carrying out the invention Process are obtained, easier to clean. Usually the temperature is in which the inventive chlorination reaction is carried out, above Room temperature and below 150 ° C. In general, the temperature is between 75 and 1500C, whereby a temperature between 85 and 1500C is often maintained.

The method according to the invention is cumbersome to a large extent use the chlorination of organic compounds, preferably a chlorination is carried out in the liquid phase. Examples of compounds that can be chlorinated are mentions the following: olefins (e.g. ethylene to ethylene dichloride), diols fine (for example 1,3-butadiene to 1,4-dichlorobutene-2), carboxylic acids (for example Acetic acid to chloroacetic acid), phenols (e.g. phenol to p-chlorophenol). Ketones (e.g. acetone to chloroacetone) and aldehydes (e.g. isobutyraldehyde to α-chloroisobutyraldehyde).

In general, they are water or an aqueous medium that is organic Solvents, such as acetic acid, may be the preferred solvents for carrying out the chlorination reaction according to the invention. Sulfolane in particular can use at least part of the water as a solvent for the chlorination reaction substitute.

When using non-reactive substrates, especially those which are gaseous at normal temperatures, such as ethylene and butadiene, it may be preferable to work in the vapor phase. This way is a much lower working pressure is required than when working in the liquid Phase is required, reaction temperatures of 150-350 ° C are possible.

Hydrogen chloride is generated during the chlorination reaction.

If water is used as the solvent, then the hydrogen chloride goes not lost as this compound dissolves in the water. An advantageous embodiment The present invention consists in using dilute hydrochloric acid as the reaction medium to use. In this way, the propensity of copper (I) chloride to polymerize effect of some organic substrates is considerably reduced. Becomes hydrochloric acid used as the reaction medium, the chlorination process can be divided into some Carry out cases advantageously in the presence of air or oxygen.

The amount of copper (II) chloride used in the chlorination reaction must at least correspond to the theoretical amount required for the reaction is (i.e. twice molar) if under conditions other than "catalytic conditions" is being worked on. This will be discussed in more detail below.

The amount of metal chloride or oxychloride in relation to that of the present invention copper (II) chloride used can vary considerably, but it will be approximate 1 mole equivalent of the additional metal chloride or oxychloride per mole of cupric chloride used in an advantageous manner.

After completion of the chlorination reaction, the chlorinated becomes organic Compound separated together with any remaining ganga material. the Residual solution of copper and metal chlorides can be mixed with air or oxygen and hydrogen chloride or chlorine for the oxidation of the copper (I) chloride in copper (II) chloride be treated. In such a regeneration stage as well as in the one according to the invention Process, the added metal has the consequence that the copper (I) chloride, which generated in solution at the chlorination stage7 - maintained as such so that the handling is simplified to the extent that the amount of liquid, required for homogeneity is reduced. The inventive Process can be carried out batchwise or continuously. In some In some cases it can be useful to have the chlorination and regeneration stages at the same time perform.

The present invention therefore relates to a continuous process for the chlorination of organic compounds, which consists in that the chlorination one or more organic cal compounds with copper (II) chloride in the presence at least one additional metal chloride or oxychloride with the exception of Alkali and alkaline earth chlorides is carried out, with the reactants in one suitable solvent are dissolved and at the same time the treatment mixture with air or oxygen and hydrogen chloride - is treated, which removes the Copper (II) chloride existing chlorinating agents are regenerated, the reaction products separate and feed unchanged material to the reaction mixture again.

As mentioned above, at least a portion of the metal chloride or oxychloride can be added to the reaction mixture in the course of the reaction.

The chlorination using copper (II) chloride can act on this Way by using only catalytic amounts of cupric chloride simultaneous treatment of the reaction mixture with air or oxygen and chlorine water substance to be carried out. If this procedure is followed, an approximate value of 0.01 - 0.1 mol of copper (II) chloride per mol of the organic substrates to be chlorinated be used. An x increase in the reaction rate is among such Conditions performed by at least one of the specified additional Metal chloride is used.

It has also been found that when carrying out certain chlorination reactions using copper (II) chloride as the chlorinating agent in the presence of at least one of the further metal chlorides specified above the reaction rate can be increased by adding an aliphatic amine hydrochloride to the reaction mixture is added.

The following examples illustrate the invention without restricting it. Examples 1 and 15 are comparative examples.

Examples 1-10 Chlorination of Phenol When performing a Each of Examples 1-10 (including one) is a mixture of 13.6 g of copper (II) chloride dihydrate (0.08 mol), a metal chloride (0.08 mol) and 1.9 g phenol (0.02 mol) in 20 ml Water under reflux and under a slow stream of nitrogen during a Stirred for a period of 1 hour. The organic product is passed out of the reactor Steam distillation removed. In each case, about 40 ml of one fall Condensate. The organic component becomes from the condensate extracted using ether. Then the ether is reduced Pressure removed.

The residues are all analyzed by gas-liquid partition chromatography analyzed. The results are summarized in the following table: Product Analysis,% (weight / weight) at- addi- weight weight, o-chlorine- phe- 2,4-di- p-chlorine play tiv des ad- g phenol nol chlorophenol ditivs phenol 1 none * 1.95 3.3 68.9 0.4 27.3 2 AlCl3 10.6 g 2.70 6.1 2.5 18.1 73.3 3 VOCla 11.0 g 2.30 10.5 21.2 1.1 67.2 4 CrCl3 12.7 g 2.81 7.1 2.7 9.9 80.3 5 MnCl2 10.0 g 2.50 8.1 4758 2.7 41.5 6 FeCl3 13.0 g 1.95 9.4 5.0 17.4 68.1 7 CoCl2 10.4 g 2.42 6.1 33.1 3.2 57.6 8 NiCl2 10.4 g 2.40 6.4 32.7 3.4 57.4 9 LaCl3 19.6 g 2.32 9.9 28.6 3.3 58.3 10 CeCl3 19o7 g 2.41 9.2 33.4 2; 0 55.3 Examples 2 - 10 show the achieved Improvements. The yield of p-chlorophenol, which in the unit of time by the Reaction of phenol with copper (II) chloride in the presence of another metal chloride has been generated almost threefold.

Example 11 380 ml of a hot aqueous solution of 170.5 g of Rupfer (II) chloride dihydrate, 266.5 g of chromium (III) chloride hexahydrate and 26 g of hydrochloric acid are in one Amount of 24 ml per hour fed to the lower part of a reaction vessel with is provided with a stirrer. Molten phenol is separated into the same reactor supplied in an amount of 1.5 ml per hour. The reactor contents are under slight Heated to reflux.

The mixed product, as well as the reactants, continuously expire Left the top of the kettle in its cooler Uberflissson. The volume of the Reactor is 25 ml, 50 that results in a residence time of 30 minutes. After this Practically equilibrium conditions have established themselves (after a 4-hour continuous operation) the organic effluent from the reactor has the following Composition as determined by gas-liquid partition chromatography analysis he can determine: 33.7% phenol, 10.6% o-chlorophenol, 2.5% 2,4-dichlorophenol and 53.2% p-chlorophenol.

Example 12 A mixture of 27.2 g of cupric chloride dihydrate (0.16 Mol), 55.6 ml of a 50% (w / w) vanadyl chloride solution (0.16 mol) and 4.1 g of concentrated hydrochloric acid (0.04 mol) is made up with water 90 ml diluted. The mixture is then heated under reverse flow, whereupon 3.76 phenol (0.04 moles) are added. The mixture is taking for 2 hours Heated to reflux. The analysis by means of gas-liquid distribution chromatography gives the following values: 4.3% o-chlorophenol, 41.4% phenol, 1.6% 2,4-dichlorophenol and 52.7% p chlorophsnol.

Example 13 The procedure described in Example 12 is repeated, however, twice the amount of phenol is used, i.

7.52 g (0.08 mole) instead of 3.76 g. All other variables will be set to the same values. After 2 hours of treatment under The organic phase is gently refluxed with stirring by means of gas-liquid partition chromatography analyzed. The following values are determined: 3.7% o-chlorophenol, 58.1 ß phenol, 0.5 ffi 2,4-dichlorophenol and 37.8% p chlorophenol.

Example 14 A mixture of 4.8 g of acetic acid, 27.2 g of cupric chloride dihydrate and 21.2 g of aluminum chloride in 50 ml of water is refluxed for 1 hour heated. The solution obtained is extracted with Xther. Wake up to the removal of the Xthers remains an oil that contains acetic acid and monochloroacetic acid.

It should be noted that the inventive method with Advantage can be applied in cases in which compliance is highly acidic Conditions is excluded, and the use of additional hydrochloric acid, as described in the German patent ... ... (patent application P 18 09 258.5, accordingly British Application No. 52178/67) is inexpedient. For example Cyclohexanone is rapidly polymerized by way of concentrated hydrochloric acid. In contrast, this compound can be replaced by aqueous copper (II) chloride chlorinate without difficulty in the presence of vanadyl chloride.

Copper (II) chloride is used in a catalytic amount and the oxidation of copper (I) chloride using oxygen and hydrogen chloride or hydrochloric acid simultaneously with the chlorination carried out, then polymerization of some substrates occurs, for example of phenols. The extent of this polymerization is determined by the presence of the inventive additional metal chlorides significantly reduced, as from the Example 16 and Comparative Example 15 below.

Example 15 A mixture of 94 g phenol (1 mol) and 8-5 g copper (II) chloride dihydrate (0.05 mole) is stirred and heated on a steam bath with hydrogen bubbling through will. 101.5 g (1 mole) of concentrated hydrochloric acid gradually becomes added over a 29 hour period. The mixture is stirred and Heated for an additional 49 hours while bubbling hydrogen. The reactor contents is then subjected to steam distillation. The aqueous phenoli see material is extracted with benzene. 59.1 g of an oil are thereby obtained .., which contains the following ingredients, as by means of gas-liquid partition chromatography found: 8.3% o-chlorophenol, 22.9% phenol, 3.8% 2,4-dichlorophenol and 65% p-chlorophenol.

flat the steam distillation stage 44.4 g of a non-volatile obtained tarry residue.

Example 16 The procedure described in Example 15 is repeated, however, the copper (II) chloride by a mixture of 6.7 g of copper (II) chloride (0.05 mol), 21 ml of a 50% (W / w) aqueous vanadyl chloride solution (0.05 mol) and 0.05 mol of a concentrated hydrochloric acid is replaced.

The additional 1 mole of hydrochloric acid will gradually, however over a period of 3 hours. After a total of during a Was stirred and heated for a period of 11 hours, with oxygen bubbling through has been, the mixture is subjected to steam distillation. The watery one Distillate is extracted with benzene. 95 g of an oil are obtained is analyzed by gas-liquid partition chromatography as follows: 1.8 % o-chlorophenol, 74.2% phenol, 0.1% 2,4-dichlorophenol and 23% p-chlorophenol. After steam distillation, the reactor becomes a non-volatile material removed in an amount of only 1.05 g. It's an easy one amber oil.

Beisiel 17 9.8 g (0.1 mol) of cyclohexanone are a mixture of 3b, 0 g (0.2 mol) of copper (II) chloride dihydrate and 33 ml (0.1 mol) of a 50% (Weight / volume) vanadyl chloride solution in 20 ml water added. The mixture is stirred at 42 ° C for a period of 3 1/2 hours and then diluted with water and extracted with ether. The distillation of the ether extract provides 7.6 g of an oil with a boiling point of 60 - 95 ° C / 15 mm. This oil contains 60% cyclohexanone and 40% 2-chlorocyclohexanone.

Example 18 A mixture of 34 g (0.2 mol) of copper (II) chloride dihydrate, 33 ml (0.1 mol) of a 50% (weight-volume) vanadyl chloride solution, 30 ml of water and 5j8 g (0.1 mol) of acetone is refluxed (79 ° C) during cooked for a period of 1/2 hour.

Acetone, chloroacetone and water are then removed from the The reaction mixture is distilled out until the head temperature has reached 95.degree. One Analysis of the distillate by vapor phase chromatography shows that 1.61 g of chloroacetone are present.

If the experiment is carried out without the vanadyl chloride solution, then the chloroacetone yield is only 0.87 g.

The scope of the invention also includes chlorinated organic compounds, for example chlorinated olefins, chlorinated acids, chlorinated phenols, chlorinated Ketones and chlorinated aldehydes, which are produced by the process according to the invention have been.

Claims (7)

Claims 1. process for the chlorination of organic compounds, whereby a or several organic compounds are chlorinated with copper (II) chloride, thereby characterized in that the chlorination in the presence of at least one further metal chloride or oxychloride is carried out with the exception of alkali and alkaline earth chlorides 2. The method according to claim 1, characterized in that the further used Metal chloride consists of aluminum chloride, vanadyl chloride or chromium (III) chloride. 3. The method according to claim 1 or 2, characterized in that the reactants are in solution. 4. The method according to any one of the preceding claims, characterized in, that is, the amount of further metal chloride used in the reaction mixture or oxychloride approximately 1 mole equivalent of the metal chloride or oxychloride per mole Copper (II) chloride is. 5. The method according to any one of the preceding claims, characterized in, daejs the chlorination in the presence of hydrochloric acid and optionally is carried out in the presence of air or oxygen. 6. Modification of the method according to claim 1 for the chlorination of organic compounds, with one or more organic compounds containing copper (II) chloride chlorinated and the reactants dissolved in a suitable solvent who the, characterized in that the chlorination in the presence at least another metal chloride or oxychloride with the exception of alkali or alkaline earth chlorides is carried out and the reaction mixture simultaneously with air or oxygen and hydrogen chloride for regenerating the copper (II) chloride chlorinating agent is treated. 7. The method according to claim 6, characterized in that a catalytic Amount of cupric chloride in a range between 0.1 and 1.0 mol of cupric chloride is used per mole of substrate in carrying out the reaction.