GB611593A - Improvements in the manufacture of primary amines - Google Patents

Abstract

Primary amines, substantially free from secondary and tertiary amines, are prepared by heating an organic compound containing one or more halogen atoms attached to carbon with ammonia in an aqueous medium containing at least 3 molecular proportions, for each replaceable halogen atom, of an ammonium halide, under a pressure sufficient to maintain the reactants in the liquid phase. Preferably, a chlorinated organic compound is heated with a moderate molecular excess of ammonia, e.g. 1.5-3 molecular proportions, in the presence of a large excess of ammonium chloride, e.g. 8, 10, 12 or 15 molecular proportions; correspondingly increased amounts being used when a di- or poly-halogenated compound is the starting material. The reaction is suitably carried out at temperatures above 100 DEG C., especially between 130 DEG and 180 DEG C., in water, though aqueous mixtures such as aqueous alcohol may be used. In an example, butyl chloride, ammonia and ammonium chloride are heated in aqueous solution in an autoclave to give butylamine hydrochloride, from which the free base is obtained by treatment with sodium hydroxide. Methyl, ethyl n-propyl, isopropyl, isobutyl and n-butyl chlorides give the corresponding amines by similar treatment. Ethylene dichloride and 1 : 6-dichlorohexane give the diamines. The process is also applicable to the preparation of amines from other organic halides having reactive halogen atoms such as aralkyl halides and aryl halides in which the halogen atom is rendered active by the presence of other substituents, e.g. benzyl chloride and o- and p-chloronitrobenzene. The Provisional Specification describes also the use of non-aqueous solvents, e.g. alcohol.