Process for preparing symmetrical and unsymmetrical N,N-dihydrocarbylhydroxylamines

摘要

A process for preparing N,N-dihydrocarbylhydroxylamines of the general formula (I) where R¹, R², R³ and R⁴ are selected independently from among hydrogen, aliphatic, cycloaliphatic, heteroaromatic and aromatic radicals, or R¹ and R² and/or R³ and R⁴ are joined to form a ring, and not more than one radical among R¹, R², R³ and R⁴ is hydrogen, which comprises the steps a) reaction of hydroxylamine H₂NOH or a salt of hydroxylamine with a compound of the general formula (II) or (III) where R¹, R², R³ and R⁴ are as defined in formula (I), b) hydrogenation of the compound formed in step a) in the presence of a catalyst, c) further reaction of the compound formed in step b) with a compound of the general formula (II) or (III) and hydrogenation of the reaction mixture in the presence of a catalyst and d), if appropriate, reaction of the salt of the dihydrocarbylhydroxylamine formed in step c) with a base.