A method for the reductive dimerization of acrylonitrile to adiponitrile

摘要

1,129,135. Reduction of organic compounds; electrolytically; adipo-nitrile. IMPERIAL CHEMICAL INDUSTRIES Ltd. Nov.25, 1965 [Dec.7, 1964; Feb.25, 1965], Nos.49713/64 and 8165/65. Heading C7B. In the reduction of organic compounds using mercury amalgam preferably in an electrolytic cell, the aqueous phase of the reaction is withdrawn and freed from organic products, and the aqueous phase containing alkali metal or alkaline earth metal ions passes to an electrolytic cell together with mercury, where the amalgam is re-formed, and the aqueous phase now depleted in alkali metals &c. is re-charged with organic starting materials, and is re-cycled to the first reduction stage. The process may be in continuous cycle including the flowing mercury cathode. The process is applied to α-#-ethylenlcally unsaturated compounds e.g. esters, amides, nitriles and especially acrylonitrile to form adipo-nitrile. The aqueous, solution normally includes valuable components e.g. tetraalkyl ammonium hydroxide or sulphonate, and N: N di-methyl nitroso-aniline, which are retained unchanged in the regeneration stage. For examples the hydro-dimerisation of acrylo-nitrile is described using these compounds in an aqueous medium containing buffer salts, and maintained at pH 5-11 by addition of phosphoric or hydrochloric acid. The figure is a flow sheet in which TeaCl is tetra-ethyl ammonium chloride. ADN is adipo-nitrile, ACN is acrylo-nitrile, and PN is propio-nitrile.