GB530269A - Improvements in or relating to the manufacture of the nitriles of organic carboxylicacids - Google Patents

Abstract

530,269. Nitriles. DREYFUS, H. June 7, 1939, Nos. 16694 and 19707. [Class 2 (iii)] Nitriles of carboxylic acids are made by dehydrating amides or ammonium salts of the acids with the anhydride of an aliphatic monocarboxylic acid such as acetic anhydride. The production of dinitriles of aliphatic acids such as suberic and sebacic acids, aromatic acids and aliphatic-aromatic acids such as benzylmalonic acid, dicyanogen, and the nitriles of higher fatty acids such as lauric, palmitic, and stearic acids is mentioned, the particular description relating to a diponitrile. The reaction temperature may be such that the aliphatic acid produced from the anhydride distils off, and a diluent which forms anazeotropic mixture with such acid may be employed, or the diluent may be of relatively high boiling-point. Preferably the amide is added a little at a time to excess of the anhydride. When an ammonium salt is the initial material a greater excess of anhydride is used, and if desired the reaction can be carried out in two stages, the ammonium salt being added a little at a time in the first stage, and then more anhydride being added to effect the second stage. In an example, adipamide is added a little at a time to a body of boiling acetic anhydride under reflux.