Process for the preparation of straight-chain acrylonitrile dimers

摘要

A process is proposed for the preparation of straight-chain acrylonitrile dimers including 1,4-dicyanobutene, 1,4-dicyanobutadiene and adiponitrile, which allows acrylonitrile to be dimerised in high yields in the presence of a ruthenium catalyst and additionally in the presence of an agent for increasing the specificity for straight-chain dimers, the agent for increasing the specificity being selected from amongst: (A) substituted benzoic acids having a benzene ring structure and a carboxyl group and at least one further substituent on the benzene ring structure, with the exception of monoalkylbenzoic acids; (B) acyclic carboxylic acids which contain a hetero atom and have a hydrocarbon skeleton, a carboxyl group which is bonded with a carbon atom of the hydrocarbon skeleton having 1 to 6 carbon atoms, and have at least one further substituent which contains a hetero atom selected from amongst sulphur and nitrogen atoms, the hetero atom of the additonal substituent being linked with a carbon of the hydrocarbon skeleton in the alpha and beta position relative to the carboxyl group; and (C) 5- to 12-membered heterocyclic carboxylic acids which have a 5- to 12-membered heterocyclic structure and contain a hetero atom selected from amongst oxygen, sulphur and nitrogen atoms, and have a carboxyl or carboxymethyl group which ... with a carbon atom of the heterocyclic structure in ... Original abstract incomplete.