GB615715A - Improvements in or relating to amines and process of forming same - Google Patents

Abstract

Amines are prepared by introducing an aliphatic aldehyde or ketone progressively into a body of an aminating agent comprising ammonia or a primary or secondary aliphatic or cycloaliphatic amine in a reaction vessel while the reaction mixture is maintained in liquid phase under hydrogen pressure at a temperature between 50 DEG and 250 DEG C. in the presence of a hydrogenating catalyst. Amino-alcohols may be prepared similarly from aldols and ammonia or an aliphatic primary or secondary amine. In a modification, polyamines are prepared by introducing an alphabeta unsaturated aliphatic aldehyde or ketone progressively into a reaction vessel containing hydrogen under pressure, a hydrogenation catalyst and ammonia or an aliphatic primary amine, the reaction mixture being maintained in liquid phase, preferably, at a temperature between 50 DEG and 250 DEG C.; the unsaturated aldehyde or ketone may have aromatic or other substituents. Generally, the aldehyde or ketone is introduced at a rate substantially equal to the rate at which it is used up. A solvent which dissolves both the animating agent and carbonyl compound may be present. In preparing the polyamines and amino-alcohols, a large excess of aminating agent may be employed and the carbonyl compound may be added in solution. In examples: (1) n-butyraldehyde is slowly introduced into a heated autoclave containing ammonia in glycerine, water or water-methanol, Raney nickel catalyst and hydrogen under pressure so yielding mono- and di-butylamines, the use of water increasing the yield of the latter; similarly, (2) proprionaldehyde reacted with ammonia in methanol yields propylamine and alpha-methylamylamine and with n-propylamine yields di- and tri-propylamines; (3) crotonaldehyde reacted with ammonia in water or water-methanol yields 1 : 3-diamino butane and mono- and di-butylamines; (4) acrolein and alpha-methyl acrolein reacted with ammonia in water-methanol yield 1 : 3-diamino propane and mono- and di-propylamines and 1 : 3-diamino-2-methyl propane and mono- and di-isobutylamines, respectively; (5) crotonaldehyde reacted with ethylamine in water-methanol yields 1 : 3-bis-ethylamino butane and N-ethyl-n-butylamine; (6) mesityl oxide reacted with ammonia in methanol yields 2 : 4-diamino-4-methyl pentane, and (7) acetaldol reacted with ammonia in water-methanol yields 4-amino-butanol-2, the result being compared with that obtained by the same process wherein all the aldol is added initially. Specification 328,381, [Class 2 (iii)], U.S.A. Specification 1,966,478, German Specification 539,104 and French Specification 37,923, are referred to.