DE2062434A1 - - Google Patents

Description

Badische Anilin- & Soda-Fabrik AG

Our reference: O.Z. 27 24-1 WB / Be

6700 Ludwigshafen, December 17th, 1970 Process for the preparation of halogen benzoyl halides

The invention relates to a process for the preparation of halogen or halonitrobenzoyl halides by saponification of appropriately substituted benzotrihalides with formic acid in the presence of catalysts.

Halobenzoyl chlorides (Bios Final Report 1145, pp and 38) on an industrial scale by saponification of the corresponding benzotrichlorides with water in the presence of sulfuric acid produced as a catalyst. This procedure requires proportionately long response times. In order to achieve good yields, the water may only be added as quickly as it the saponification rate of the benzotrichloride to benzoyl chloride is equivalent to. If water is added more quickly, halobenzoic acid is undesirably formed.

It is known from Journal of the University of Bombay 1937, Part 2, pages 112 ff. That unsubstituted benzotrichloride is reacted with a stoichiometric amount of formic acid at 100 ° C. to form a mixture of benzoic acid and benzoyl chloride. It is also known that the reaction of unsubstituted benzotrichloride with chloroacetic acid without a catalyst at 100 to 120 ^° C. or in the presence of zinc chloride at 80 to 90 ^° C. gives a mixture of chloroacetyl chloride and benzoyl chloride (C. 1929 II, 2766). When benzotrichloride is not substituted with glacial acetic acid, acetyl chloride and BenzoylchLorld are formed (B. 67 (1934), 370-372)). The corresponding reaction with acetic acid gives the theoretical amount of benzoic acid. The Belgian patent 714 889 shows that halobenzal halides are saponified with formic acid in the presence of halides of the metals of the 2nd, 7th, 8th subgroup * 3rd or 5 "main group of the periodic system" to give the corresponding benzaidehydes.

^328/70 209826 / IiOO BAD

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It has now been found that halogen or halonitrobenzoyl halides are advantageously obtained by saponification of appropriately substituted benzotrihalides with an acid at elevated temperature in the presence of catalysts if the saponification is carried out with formic acid as the acid and in the presence of halides of the metals of the 2nd, 7th ., 8th subgroup % or 5th main group of the periodic table performs as catalysts.

The reaction can be carried out in the case of using 2,6-dichlorobenzotrichloride represented by the following formulas:

01
/ ~ V_CC1 ₃ + HCOOH

Cl Cl

Compared to the aforementioned method, the method delivers according to the invention in a simple and economical way Halobenzoyl halides in shorter reaction time, good yield and purity. The method allows safe, trouble-free operation of the Investments. In view of the prior art, these advantageous results are surprising, one would have jzuiaineieöfe to a considerable extent a conversion to substituted benzoic acid ^ Instead of the Benzoy! halides you have to expect.

The starting materials used are benzotr, halides, preferably chlorides, which are substituted one or more times by hats, and optionally by nitro groups ¹ in 2- ttffl 4-S bei lung, eliie iHtrögruppe, a Bröiä-, iodine tiM / öier vötziigs-wise Chlörätora fcrageii.

The following substituted benzo tr Ihälögentide can be used as "starting materials" 2-OhIOr- * 4-Giiiör-i 2,4- ^ 5 * §- \ or 2,6-Dichlör-, 2,4 * 6-, 2,3 * 5-'Brichlör- _i M,: Miä-Mi§eMdr- \

^sfa ORIGINAL

- 3 - O.Z. 27 241

2-chloro-6-nitro-, 2-chloro-4, 6-dinitro-, 2-bromo-4-chloro-6-nitro-, 2,4 - dibromo-6-iodo, 2,6-diiodo, 3,5-dibromo, 2-bromo-4-nitrobenzotrichloride or corresponding bromides or iodides.

The saponification agent used is formic acid, which is still up to can be diluted to 10 wt. # with water. One can use formic acid in excess, for example in an excess of up to 0.4 mol over the stoichiometric amount, or preferably in a stoichiometric amount Use amount.

The reaction is carried out at a temperature between 70 and 180 ^° C., preferably between 80 and 150 ^° C., in particular between 120 and 150 ^° C., without pressure or under pressure, batchwise or continuously. If appropriate, solvents such as aromatic chlorohydrocarbons, for example di- or trichlorobenzene, can be used.

The catalysts used in the saponification are halides of the metals of the 2nd, 7th, 8th subgroup, and the 3rd or 5th main group of the periodic table. Preferred catalysts are bromides, iodides or, in particular, chlorides of the metals cadmium, aluminum, Antimony, arsenic, manganese, mercury, boron, cobalt, nickel or especially iron or zinc. Mixed catalysts can also be used can be used with several of the aforementioned metals and / or halides. The halide used as a catalyst can also only be formed during saponification; for example, corresponding oxides, hydrated oxides, salts weak or organic acids of the aforementioned metals and the metals themselves, which in the reaction by themselves forming hydrogen halides are converted into their halides, fed to the reaction. Generally used the catalyst is substituted in an amount of 0.001 to 0.1 mol, preferably 0.005 to 0.05 mol, based on 1 mol Benzotrichloride.

The reaction can be carried out as follows: A mixture of substituted benzotrihalide, formic acid, Catalyst and optionally solvent within 1 hour to the aforementioned temperature and then leaves the mixture

209 8 2 6/1100 -4-

- 4 - O.Z. 27 241

react for a further 1 to 3 hours at this temperature, whereby. Develop hydrogen halide and carbon oxide. One can but also more advantageously the substituted benzotrihalide together with the catalyst, e.g. for 30 minutes at reaction temperature Warm up and then let the formic acid flow in slowly, e.g. over 1 to 3 hours. Kun isolated the end product is removed from the reaction mixture in the usual way, e.g. by fractional distillation under reduced pressure.

The compounds which can be prepared by the process of the invention are valuable starting materials for the preparation of herbicides and dyes. Further saponification leads to the corresponding benzoic acids, which are used in Ullmanns Encyklopadie der technischen Chemie, Volume 4, pages 286 ff. Stated 1st.

The parts given in the following examples are parts by weight.

example 1

230 parts of o-chlorobenzotrichloride and 2 parts of zinc chloride are heated in a stirred vessel provided with a reflux condenser and a gas outlet, at 130 ⁰ C. Then 46 parts of formic acid are allowed to flow in over the course of 2 hours. The reaction takes place with strong formation of hydrogen chloride and carbon oxide. Wax feed of the formic acid the temperature is increased to 145 ⁰ C. The mixture is stirred at this temperature for a further 0.5 hours until the evolution of gas ceases.

177 parts of reaction mixture are obtained and, by vacuum distillation, 168 parts of o-chlorobenzoyl chloride (a yield of 96 # according to theory), with a boiling point of ₂₀ 117 ^° C.

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- 5 - OZ 27 241

Example 2

To a mixture of 230 parts of p-chlorobenzotrichloride and 2 parts of zinc chloride in a vessel equipped with a reflux condenser and gas outlet is allowed to stirred vessel at 130 ⁰ C within 3 hours 46 parts of formic acid accrue. After the formic acid has been added, the mixture is heated at 145 ^° C. for a further 1/2 hour.

180 parts of reaction mixture are obtained and, by vacuum distillation, 166 parts of p-chlorobenzoyl chloride (yield: 95 % of theory) with a temperature of ₂₀ 114 ^° C. are obtained

209326/1100

Claims (1)

- 6 - O.Z. 27 Claim Process for the preparation of halogen or halonitrobenzoyl halides by. Saponification of appropriately substituted benzotrihalides with an acid at elevated temperature in the presence of catalysts, ■ characterized in that the saponification with formic acid as the acid and in the presence of halides of the metals of the 2nd, 7th, 8th subgroup od.3.oder 5. Performs main group of the periodic table as catalysts. Badische Anilin- & Sodafabrik AG 209826/1100