SU454203A1 - Method for preparing carboxylic acid nitriles - Google Patents

Description

The invention relates to methods for producing nitriles of carboxylic acids, important intermediates in the synthesis of organic substances used in the medical industry, chemistry of dyes, etc.

A known method for producing nitriles of carboxylic acids of an aliphatic or aromatic series, for example acetonitrile, benzonitrile, by reacting the sodium or ammonium salt of the starting carboxylic acid, for example sodium benzoate, phosphonitrile chloride and ammonium chloride at boiling at 200-230 ° C. The output of benzonitrile 76%.

In this method, the process proceeds under rather severe conditions (temperature 200 ° C) and it is necessary to trap the released hydrogen chloride. The method allows to obtain nitriles of carboxylic acids of the aromatic and aliphatic series with a yield of about 76%.

In order to simplify the process, expand the product range and increase the yield of the target products, it is proposed to treat the corresponding carboxylic acid or its ammonium salt with a cyclic phosphonyltrichloride oligomer — hexachlorocycloprifosphate-yrene-boiling at 100–180 ° C in an organic tertiary amine medium, for example, pyridine, triethylamine or diethyl ethylamine, and for example, pyridine, triethylamine or diethyl ethylamine; with the subsequent selection of the target product by known techniques.

2

According to the proposed method, nitriles of carboxylic acids with higher yields and under milder conditions are obtained, eliminating the need to trap the effluents with hydrogen chloride. In addition, this technique expands the possibilities for the synthesis of nitriles, since it allows one to obtain not only nitriles, but also the synthesis of carbopic acids of the aliphatic and aromatic series.

The method is as follows. The carboxylic acid or its ammonium salt is mixed with hexachlorocyclopulphosphate sodium and boiled at 100-180 ° C in a tertiary amine medium, for example pyridine or quinoline.

Example 1 Into 25 ml of anhydrous pyridine, 5.25 g of hexachlorocyclo triphosphazateriene is dissolved and 6.21 g of ammonium benzoate is added. The mixture was agitated, stirring, for 1 hour at 110 ° C, protecting against the ingress of air moisture, patronol with calcium chloride, cooled to room temperature, and 75 ml of 10% hydrochloric acid was added. The reaction product is then distilled off with steam, extracted with ether, dried over sodium sulfate and distilled. Obtain 4.5 g of benzonitrile (97.2%), t. Kip. , n ° 1.5280

(1.5282).

PRI and m er 2. To 5.25 g of hexachlorocyclopulphosphate sodium in 25 ml of anhydrous pyridine