GB805018A - Production of alkylamines - Google Patents

Abstract

Alkyl primary amines are obtained by hydrolysis of N-alkyl-formamides with at least one mol. of sulphuric acid in the presence of water, the mixture being heated to at least 160 DEG C. under autogenous pressure until the liberated formic acid is substantially completely decomposed. The process is particularly applicable to the N-alkyl-formamides obtained by reacting a secondary or tertiary olefin with hydrogen cyanide in the presence of sulphuric acid and water and the hydrolysis step may be carried out without isolation of the formamide. The hydrolysed reaction mixture is neutralized with an alkali metal, alkaline earth or ammonium hydroxide and the amine isolated, e.g. by distillation. Examples show (1) the production of dodecylamine by hydrolysis of the product from propylene tetramer and hydrogen cyanide; (2) sec- and t-butylamines similarly from butene-1 and isobutylene; (3) the hydrolysis of N-n-propylformamide. The process is also applicable to N-alkyl-formamides where the alkyl group is methyl, ethyl, isopropyl, n-butyl, n-pentyl, isopentyl, 2-methylbutyl-2-, 2-methylpentyl, n-hexyl, 2-ethylhexyl, iso-octyl, 2 : 4 : 4-trimethylpentyl, hexyl-(propylene dimer), nonyl-(propylene trimer) and dodecyl (butene trimer). It is preferred to use 1-1.5 mol. of sulphuric acid and at least 1 mol. of water for the hydrolysis per mol. of amide.