Process for the manufacture of cyclopropylamine

Abstract

A modified novel process for preparing cyclopropylamine from .gamma.-butyrolactone is described. The .gamma.-butyrolactone ring is cleaved with a hydrohalide in the presence of a novel catalyst comprising an aqueous sulfuric acid solution. The 4-chlorobutyric acid, thus formed is converted into a hindered chlorobutyrate ester. The hindered ester based on secondary and tertiary alkanols of eight or less carbon atoms, is cyclized to form the hindered cyclopropanecarboxylate ester by a novel reaction medium consisting of solid caustic in a water-immiscible solvent and a phase transfer catalyst. The hindered cyclopropanecarboxylate ester is ammoniated to form cyclopropanecarboxamide by a novel catalyst comprising an alkali metal salt of a polyol having hydroxy groups on adjacent carbons. The carboxamide formed in substantially quantitative yields is converted to cyclopropylamine by a modified Hofmann reaction utilizing continuous degradation of the intermediate with simultaneous distillation.