Patent ID: 7396959
Filing Date: 2008-07-08
Classification: C07C

Abstract:
1. A process for preparing an N,N-dihydrocarbylhydroxylamine of the general formula (I): wherein R 1 , R 2 , R 3 and R 4 each independently represent a moiety selected from the group consisting of branched or unbranched aliphatic, cycloaliphatic, heteroaromatic and aromatic radicals having from 1 to 32 carbon atoms, or R 1 and R 2 and/or R 3 and R 4 are joined to form a ring having a total of from 3 to 12 carbon atoms, the process comprising: a) reacting hydroxylamine H where R 1 , R 2 , R 3 and R 4 are as defined in formula (I) to form an oxime intermediate, b) hydrogenating the oxime intermediate in the presence of a catalyst comprising a noble metal to a hydrogen consumption of from 60 to 130 mol % of theory, to form a corresponding monohydrocarbylhydroxylamine or a salt of the corresponding monohydrocarbylhydroxylamine, and c) reacting the monohydrocarbylhydroxylamine or salt thereof with a compound of the general formula (II) or (III) with hydrogenation of the reaction mixture in the presence of a catalyst comprising a noble metal to a hydrogen consumption of from 60 to 130 mol % of theory, forming a corresponding dihydrocarbylhydroxylamine or a salt of the corresponding dihydrocarbylhydroxylamine, with the proviso that where a salt of hydroxylamine is reacted with a compound of the general formula (II) or (III), the process further comprises reacting of the salt of dihydrocarbylhydroxylamine with a base.