GB1187616A - Production of Adiponitrile - Google Patents

Abstract

1,187,616. Dimerization of acrylonitrile to adiponitrile. TOYO KOATSU INDUSTRIES Inc. 16 Oct., 1967 [18 Oct., 1966], No. 46971/67. Heading C2C. Adiponitrile is obtained by reductively dimerizing acrylonitrile by reacting an aqueous solution of acrylonitrile with an alkali or alkaline earth metal amalgam and acid in the presence of an optionally substituted tetraalkyl arsonium compound as a catalyst and maintaining the pH of the reaction solution at 2-12, the acid used being an inorganic or organic acid or a substance capable of providing acidity in the aqueous solution. The tetraalkyl arsonium catalyst employed is suitably of the formula wherein R<SP>1</SP>, R<SP>2</SP>, R<SP>3</SP> and R<SP>4</SP> are C 1-20 alkyl radicals which may be substituted, e.g. by -OH or -Br, and [X-] is an anion chosen from Cl-, Br-, I-, SO 4 =, RSO 4 - wherein R is a C 1-4 alkyl radical, SCN-, OH-, PO 4 #, the sulphonic acid anion, a carboxylic acid anion, the benzoic acid anion or the phosphonate anion, and it may be used in an amount of 0-0001 to 0À01 mol per mol of acrylonitrile. The acid employed may be hydrochloric, sulphuric, acetic or a sulphonic acid, carbon dioxide or sulphur dioxide, and the reaction is suitably effected at a temperature of 10-50‹ C. An organic solvent capable of dissolving the acrylonitrile in water may be present, suitable solvents being mono- and dialkylamides, dialkyl sulphoxides, dialkylsulphones, hexaalkylphosphoramides, aliphatic alcohols, acetone, N-methyl pyrrolidone and acetonitrile and the amalgam employed, which is suitably of a concentration of 0À015 to 0À7% by wt., is preferably sodium or potassium amalgam. Suitable forms of apparatus in which the process may be carried out are described and the product mixtures obtained may be worked up by conventional methods.