GB728702A - Process for the production of amines - Google Patents

Abstract

Amines are produced by mixing an aliphatic or cycloaliphatic aldehyde with ammonia or a primary or secondary amine at a temperature below 0 DEG C. and thereafter hydrogenating the mixture in the liquid phase at elevated temperature and pressure. The hydrogenation is preferably carried out in the presence of a hydrogenation catalyst, such as a catalyst containing cobalt or nickel. The aldehyde is preferably diluted with a low boiling solvent such as an alcohol or a hydrocarbon. The process may be carried out batchwise or continuously. Aliphatic and cycloaliphatic aldehydes of any kind may be used, e.g. unsaturated aldehydes, hydroxyaldehydes and dialdehydes. In the examples: (a) propionaldehyde mixed with methanol is treated with ammonia at - 15 DEG C.; a nickel catalyst is added and hydrogen is then introduced under pressure; the mixture is heated to give propylamine; (b) an Oxo synthesis product containing 62 per cent of C7 aldehyde and 38 per cent of C6 hydrocarbon is subjected to the process of (a) to give primary C7 amine and diheptylamine; (c) methyl ethyl acrolein is similarly treated to give 2-methyl-pentylamine and some propylamine; (d) propionic aldol is similarly treated to give hexanolamine and propylamine; (e) propionaldehyde is treated as in (a), except that propylamine is used instead of ammonia, to give dipropylamine; (f) butyraldehyde mixed with methanol is cooled to - 10 DEG C. and treated with ammonia and then hydrogenated at elevated temperature and pressure to give a mixture of primary and secondary butylamine; (g) tricyclodecane methyl aldehyde, which is prepared from dicyclopentadiene by the Oxo synthesis, is treated with ammonia at - 5 DEG C. and subsequently hydrogenated to give tricyclodecanemethylamine; and (h) camphene aldehyde, produced from camphene by the Oxo synthesis, is similarly treated to give camphene methylamine.