DE1443829A1 - Process for the preparation of chlorine-substituted benzene derivatives - Google Patents

Description

Dr. Expl.

BRAUN8OHWEIQ, 13 «, April 1962 AT THE CIVIL PARK 8

144382a

Sr / Be - F 143

Fuso Chemical Go ", Ltd., 10, 3-ohome, Nonaka Kitadori, lfigashiyodogawa-7 / Osaka, Japan

KU

DR. MÜLLER-BORi DIPL.-INQ. QRALFS

PATENT LAWYERS

Process for the preparation of chlorine-substituted benzene derivatives

The invention relates to a process for the preparation of chlorine-substituted benzene derivatives and "relates in particular to on the production of chlorine-substituted benzene derivatives of the following general formula:

«■ " ρ

- 01

In this formula, X = H or 01, Y = H, -CCl ₃ , -COOH or -COCl and Z = H or one of the groups mentioned in the definition of Y? in this case Z is in the m or p position to the group Y _e The compounds of the formula I are known

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Bs is known to produce chlorine-substituted trichloromethylbenzene by chlorination of, for example toluenesulfonyl chloride at 150-20O ⁰ C, (G., 1898, II, 80Oj ax ₀ H 5, 300, 303 $ DHP. 98433). Since this process requires high temperatures, it is accompanied by undesirable chlorolysis, which causes the product to darken and resinify and leads to the product being obtained in low yield and low purity.

It is also known the chlorination of sodium p-toluenesulfonate or p-toluenesulfonyl chloride with thionyl chloride to be carried out under pressure at a high temperature of 230-260 C (Appendix. ΕΓΠ ,, 24, 26j C. 19JL5, I> 464f DRP. 282 133 $ M. 16_, 730) ο In any case, you have to be unnecessary employ high temperatures or pressures and therefore these methods are not economical and industrially useless

Because of these difficulties, it has become customary to produce, for example, chlorine-substituted trichloromethylbenzenes, by reacting toluenes, which are substituted in the desired position with a chlorine atom, with chlorine gas at a temperature of 80-165 ° C. in the presence of a catalyst such as phosphorus trichloride, with only the methyl radical on the benzene ring (PB 77764 (No ₉ 33) £ 25602 $ 17658)

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is selectively trichlorinated. This method is satisfactory to a certain extent, but has the disadvantage that the starting materials, for example o- or p-chloro-substituted Toluene or xylene, have to be very pure and are therefore expensive.

It is therefore a general object of the invention to provide a process for the preparation of chlorine-substituted To develop trichloromethyl- or bis-trichloromethylbenzenes, which are easy and cheap (with less expensive starting materials) and the desired products in excellent yield and purity supplies.

The more detailed aim of the invention is a process for the preparation of chlorine-substituted trichloromethyl or to develop bis-trichloromethylbenzenes, which makes it possible to use chlorine-substituted or unsubstituted starting materials To use toluene or xylene sulfochlorides, which are less expensive than those commonly used, in ortho or para position with chlorine-substituted ones Toluenes or xylenes,

A further aim of the invention is to develop such a method that takes place at a relatively low temperature without an accompanying undesired chlorolysis and without chlorination of the directly with the Ringkonienstoffatomen

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ORIGINAL INSPECTED

linked hydrogen carry out so that the desired products are obtained in excellent yield and purity »

It is also the aim of the invention to provide an economical process for the preparation of derivatives (such as
Acid chlorides, carboxylic acids, etc.) from the above-mentioned chlorine-substituted trichloromethyl or bis-trichloromethylbenzenes ₀

Other objects, features and advantages of the invention
result from the following detailed description

It was found that when implementing a
Toluene or xylene sulfochlorides or a chlorine-substituted toluene or xylene sulfochloride with chlorine in
an inert polychlorinated aliphatic or
aromatic hydrocarbon under irradiation with
UV light and / or, in the presence of a catalyst which delivers free radicals, trichlorination of the or »the
Methyl radicals on the benzene ring and further a chlorine exchange reaction on SuIfochloridradikal at low temperature (60-9O ⁰ C) enters, without an undesirable chlorolysis or chlorination takes place on the benzene ring, except for the replacement of the SuIfochloridradikals against a chlorine atom.

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_ 5 -

The reaction can be formulated by the following general scheme:

X X

0-SO ₂ Cl ⁰¹ 2, / \ -Gl + S0 ₂ + 3HCl (od _e 6HC1) GH, UV light R ¹ X = A GGl * ⁰ or Kata- ^J

(II) analyzer (III)

In these formulas, X is hydrogen or chlorine, the radical R in formula II is in para or meta position to the methyl radical and denotes hydrogen or a methyl group, and the radical R ¹ in formula III is in para or meta position to the trichloromethyl radical and means hydrogen or a trichloromethyl group

The starting materials, chlorine-substituted or unsubstituted toluene or xylene sulfochlorides Formula II, which are used in the process according to the invention, are less expensive than toluenes or xylenes, which are substituted by chlorine in the ortho or para position and which have hitherto usually been used as starting materials for the preparation of compounds of the same type as were used by the process according to the invention are accessible.

Preferably the process of the invention is carried out using o- or p-toluenesulfochloride, 3-chloro-4-methylbenzenesulfochloride and p- or m-xylene sulfochloride

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ORIGINAL INSPECTED

carried out as a compound of formula II

According to the invention, the reaction medium used is a polychlorinated aliphatic or aromatic hydrocarbon which is inert to chlorination. Examples of such hydrocarbons are chloroform, carbon tetrachloride, dichlorobenzene, trichlorobenzene, chlorosubstituted trichloromethylbenzene and chlorosubstituted bis-trichloromethylbenzene of the formula III below, for example derivatives of the formula III given formula IV and carboxylic acids of the formula V * given below are to be prepared, as will be explained in more detail below, it is particularly advantageous to use a chlorine-substituted trichloromethylbenzene or bis-trichloromethylbenzene which is identical to the desired product _o The amount of the reaction medium or solvent is not critical, but it is preferred to use the medium in an amount of 1-10 parts by volume per part of starting material ₀

The inventive chlorination proceeds according to the so-called free radical chain reaction and is under irradiation with ultraviolet light and / or providing in the presence of a free radical catalyst performed ₀ Examples of catalysts which provide free radicals and can be used in the method of the invention are azobis compounds, such as azobisisobutyric acid nitrile

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Azole disisovaleric acid nitrile, organic peroxides, in particular Acy Ip er oxy de, such as lauroyl peroxide, benzoyl peroxide, 4-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide etc". Also, a mix of two or more of these Catalysts can be used «In general, azo bis compounds are particularly useful for accelerating the Chlorination suitable in the initial stage, while organic peroxides are effective in keeping the reaction going. If that Process is carried out on a large scale, it is therefore recommended to use a mixture of the azobis compounds and use organic peroxides. The amount of catalyst can vary greatly depending on the reaction conditions, however, a satisfactory result is achieved when the Catalyst in an amount of 0.5 to 3 mole percent, based on the starting compound (Formula II) is used.

To carry out the process according to the invention, the starting material or the sulfochloride is the Formula II is dissolved in a reaction medium or solvent, and chlorine gas is introduced into the solution while this is irradiated with ultraviolet light. The UV lamp is preferably placed as close as possible to the reaction vessel brought up. Instead, you can also introduce chlorine gas into a reaction mixture, which consists of the starting material, the catalyst and the reaction medium.

In any case, the chlorine gas is incorporated into the solution

passes while it is maintained at a temperature of 60-90 C, preferably 60-8O ⁰ C. First, the chlorine gas is slowly introduced until saturation is reached »In a few minutes after saturation, the reaction starts with vigorous evolution of sulfur dioxide and hydrogen chloride no excess chlorine escapes from a gas outlet of the reaction vessel.

In general, in about 3 to 5 hours chlorine gas in an amount of about 70 to 80 $ »theory absorbed (calculated as 3 moles of chlorine per methyl radical and 1 mole per Sulfoehioridradikal in the starting compound), and then the reaction rate decreases gradually, while the rate of introduction of the chlorine gas is reduced in accordance with the rate of absorption and the reaction is further continued . After a total of about 20 to 30 hours, the reaction is complete. The total amount of chlorine, including some losses of chlorine through the escape of the gas outside the reaction vessel, is usually up to about 90% of the theoretical amount.

Sas procedure is said to be in the presence of as little water be carried out as possible, and therefore precautions must be taken to ensure that the reaction units used

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taker and the reaction medium in an anhydrous state present »

When the reaction is complete, the resulting mixture can be distilled in order to recover the solvent and to purify the desired products of the formula III. Since the catalyst has »replaced itself at the end of the reaction, there is no danger" during the distillation Starting material according to formula II less expensive. The reaction can be carried out smoothly under mild conditions, especially at low temperature, so that no side reactions, e.g. chlorolysis, undesired chlorination of the benzene ring, etc., occur and the desired product is therefore in excellent yield (for example up to about 96 % or higher) and purity, the chlorine atom released from the sulfochloride radical contained in the starting material contributes to the chlorination reaction, so that the amount of chlorine gas to be introduced may be smaller than theoretically required.

Another major advantage of the invention The process is that the solution resulting from the chlorination is practically free of all undesirable By-products and can therefore be directly subjected to hydrolysis to form derivatives such as acid chlorides and esters

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and to produce gartonic acids of the compounds according to formula III. As explained above, if you want to prepare a derivative of this type, the reaction medium used is preferably the compound according to formula III _r, which is identical to the product from which the derivative is obtained ₀

The hydrolysis can be carried out in the usual way. To produce acid chlorides, for example, the solution obtained in the chlorination reaction is subjected in the usual way to partial hydrolysis with a theoretical amount of water in the presence of a catalyst that splits off hydrogen chloride, such as FeCl., ZnOl _2, etc. Hydrolysis can be formulated as follows:

H ₂ O

R '"\ - = / ^ GGl, catalyst R ¹ " ·

(III) (IV)

In these formulas, the substituents X and R ^{1 have} the same meaning as above, and the substituent R "'in formula IV is in the m- or p-position to the -COÖl-G group and means H or -COG1»

Carboxylic acids are desired, which is made from the The solution resulting from the chlorination reaction is carried out in the usual way

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U43829

hydrolysis in an acidic or alkaline medium subject to:

\ ^H 2 ° ₃ / \ -01

/ "\ -Cl ^H 2 °

5 alkali R '»X = J * COOH

or acid
(III) (V)

X and H ¹ again have the same meaning as above, and R ^w in formula V is in the p- or m-position to the -COOH group and denotes H or -COOH.

The corresponding esters can be prepared by adding the solution formed in the chlorination reaction is subjected to alcoholysis in the usual way.

In any case, acid chlorides, carboxylic acids and later are obtained easily and in excellent yield.

example 1

A 300 al Quare flask equipped with a gas inlet pipe, gas outlet pipe and thermometer was echioctated with 19.1 g of freshly distilled p-toluenesulfochloride and 190 ml of carbon tetrachloride. Under irradiation of a 100 watt UY-La * pe _f which was arranged at a distance of β cm from the piston surface "Ohlorgae long" in the ^{solution kept at a temperature of 70-1 0} C until door

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Saturation initiated. .After about 10 minutes disappeared applies color of chlorine, and a vigorous evolution of hydrogen chloride and sulfur dioxide began, making the start of the reaction indicated "After insertion of the reaction, the feed rate was increased the chlorine gas and adjusted so that the outlet of excess Chlorine gas from the gas outlet pipe has been avoided. After about 5 hours, the reaction rate gradually decreased and the rate of introduction of the chlorine gas was decreased accordingly. The reaction was continued for a total of 32 hours. After the separation of the carbon tetrachloride, the resulting pale yellow transparent solution was subjected to vacuum distillation. There were 21.75 g (yield 94.5 $) of p-chlorobenzotrichloride, bp. 125 - 135 ⁰ C / 20 mm, d = 1.495 (15 ° C) was obtained. The hydrolysis of the product gave almost the theoretical amount of p-chlorobenzoic acid, but no p-chlorobenzaldehyde.

Example 2

For a mixture of 95.3 g freshly distilled at a temperature between 68 and 72 ° C p-toluenesulphonyl chloride, 0.8 g of aeobisisobutyric acid nitrile and 980 ml of carbon tetrachloride became chlorine gas for 30 hours initiated to effect the chlorination as in Example 1. After the reaction, the obtained one turned light yellow

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Solution subjected to vacuum distillation. There were 105.3 g (yield 91.5 ⁰ A) from virtually farblosem.transparentem, p-chlorobenzotrichloride, bp. 125 - 135 ° O / 2O mm, a β 1,496 (15 ⁰ C).

Example 3

The procedure of Example 2 was repeated except that was used instead of carbon tetrachloride, chloroform and the chlorination reaction was carried out at 60 ⁰ C. The resulting solution was subjected to vacuum distillation after the chloroform had been evaporated off. This gave 103.5 g (yield $ 90) of practically colorless, transparent p-chlorobenzotrichloride, boiling point 125-135 ° C./20 mm.

Example 4

⁰ G

One at a temperature between 67 and 71

A maintained mixture of 323 g of freshly distilled p-toluenesulfonyl chloride, 4.1 g of benzoyl peroxide and 1600 ml of carbon tetrachloride was introduced for 32 hours with chlorine gas to effect the chlorination as in Example 1. 450 g of chlorine were introduced during the reaction. The resulting solution was distilled. Kp was obtained 376 g (yield 96.4 #) practically colorless p-chlorobenzotrichloride. 125 - mm 135 ⁰ C / 20.

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-H-

Example 5 ' ^{: i} -

In a maintained at a temperature between 68 and 71 ⁰ C mixture of 95 »3 of freshly distilled g of o-toluenesulfonyl chloride, 2 g of lauroyl peroxide and 980 ml of carbon tetrachloride 32 hours Ohlorgas was introduced to the chlorination to effect as in Example. 1 In the distillation, the resulting solution Kp were 103.2 g (yield 89.7 ° i) is practically colorless, transparent o-chlorobenzotrichloride, 130 -. HO ⁰ C / 20 mm obtained

Example 6

As in Example 1, chlorine gas was passed into a mixture of 112.5 g of freshly distilled 3-chloro-4-methylbenzene sulfochloride, 1.5 g of benzoyl peroxide and 562 ml of carbon tetrachloride, as in Example 1, to prevent the chlorination 3OV3 Hours to effect. When the resulting pale yellow solution was distilled, 105.1 g (yield $ 79.4) of practically colorless and transparent 2,4-dichlorobenzotrichloride, boiling point 150-16O ⁰ C / 20 mm were obtained »

Example 7

In a kept at a temperature between 68 and 70 ⁰ C mixture of 102.3 g of m-xylene-4-sulfochloride

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(Kp.'158 - 159 ⁰ C / 16 mm), 1.2 g benzoyl peroxide, 0.8 g of azobisisobutyronitrile and 510 ml of carbon tetrachloride, chlorine gas was introduced as in Example 1 to effect the chlorination 3OY2 hours "The resulting solution was. subjected, after separation of carbon tetrachloride vacuum distillation · Man 140 received g (yield 80.6 fo) of 4-chloro-1,3-bis-trichloromethylbenzene the product was a yellowish transparent viscous liquid (b.p. 163 -.. 168 ⁰ C / 8.5 mm, d = 1.623 at 15 ° C.) and gave 4-chloroisophthalic acid in excellent yield on hydrolysis.

Example 8

The procedure of Example 7 was repeated except that p-xylene sulfochloride was used in place of m-xylene-4-sulfochloride used. The resulting solution was distilled, it provided 136 g (yield 78.3 #) of yellowish, transparent 2-chloro-1,4-biB-trichloromethylbenzene (b.p. 162-168 ° C / 8.5 mm), which during hydrolysis is monochloroterephthalic acid in excellent yield.

Example 9

To one kept at a temperature of about 70 C. Mixture of 5 kg of raw, dried p-toluenesulfochloride, 7.5 g p-chlorobenzotrichloride, 0.021 kg azobisisobutyric acid ^

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nitrile and 0.063 kg benzoyl peroxide became continuous. Ghlorgas initiated after about 5 hours increased the rate of absorption of chlorine, so that the temperature of the reaction mixture increased to about 80 ⁰ C was "Chlorination was continued and the reaction was complete after a total of 23 hours. Then became dry

Air is blown in for about 80 ⁰ C warm solution, "to expel hydrogen chloride and excess chlorine were obtained 13" 64 kg of crude p-uhlorbenzotriChlorid, the bright yellow and was transparent, and at 15 ° C a density of d = 1.498 possessed · When Distillation gave this crude product a purified fraction (bp 125-135 ° C / 20 mm) in an amount which was 95 "ß> of the crude product and a yield of about 90 to 91 ^σ / ° of theory«

A mixture of 10 kg of the above crude p-chlorobenzotrichloride, 50 kg of water and 0.06 kg of a cationic surfactant was ^{stirred for 20 hours at a temperature between 90 and 92 °} C. to effect hydrolysis. After cooling, the formed Crystals were separated, washed with water and dissolved in aqueous sodium hydroxide solution.The solution was treated with activated charcoal and acidified with sulfuric acid to precipitate the hydrolyzed product.This gave 6.14 kg of colorless crystalline p-chlorobenzoic acid (b.p. 234.5-237 , 5 ⁰ C) obtained (yield 86.5 #, based on the crude p-toluenesulfochloride.

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Example 10

To a mixture of 75.9 kg of the high p-chlorobenzotrichloride obtained in Example 9 and 0.068 kg of anhydrous ferric chloride, which was kept at a temperature of 90-94 ° C., 5.387 kg of water were added dropwise with stirring over the course of 20 hours, in order to bring about a partial hydrolysis ”) Then dry air was blown into the resulting liquid at a temperature of 90-94 ⁰ O for 30 minutes, and the liquid was distilled in vacuo. 48.83 kg (yield 83.04 %) were obtained _t based on the charged high p-toluenesulfonyl) of colorless p-chlorobenzoyl chloride, bp _{0135 to} 137.5 ° C / 50 mm.

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Claims (4)

Claims Process for the preparation of chlorine-substituted benzene derivatives the general formula (D in which X = H or Cl, Y = H, -CCl _3, -COOH or -COCl, and Z = H or a radical as Y "and Z is in the m- or p-position to the radical Y, characterized, that you can get a compound of the formula (II) </ \ -SO ₉ Cl 2 ^V in which X has the same meaning as before and R is in the p- or m-position to the -CH ^ radical and is hydrogen or represents a methyl group in an inert medium under irradiation with ultraviolet light or reacts with chlorine in the presence of a free radical catalyst and, if necessary, the reaction product subject to hydrolysis ", 809812 / U21 ■ U43829 2. The method according to claim 1, characterized in that the chlorination is carried out at a temperature of 60-90 ⁰ G, 5. The method according to claim 2, characterized in that an azobis compound and / or a catalyst organic peroxide is used. 4. The method according to any one of the preceding claims, characterized in that a polychlorinated aliphatic or aromatic medium is used as the inert medium Hydrocarbon is used. 809812 / U21