GB931582A - Process for the preparation of dimethylhydroxylamine - Google Patents

Abstract

N,N-Dimethyl hydroxylamine is prepared by oxidising dimethylamine with hydrogen peroxide in a liquid reaction medium which dissolves both in the presence of an oxide, oxy acid or alkali metal salt thereof, or selenium, molybdenum, tungsten, vanadium or uranium as catalyst, the preferred solvent being water or a C1 to C4 alkanol or a mixture thereof, acetone, methylethyl ketone and diethyl ketone also being named. Preferred operation is at -20 DEG to +20 DEG C. Preferred catalysts are the alkali metal tungstates, molybdates or vanadates, or selenium dioxide, in preferably 1-5% by weight relative to the weight of dimethylamine, although 0.5 to 10% may be used. Hydrogen peroxide of any concentration may be employed, in aqueous or alcoholic solution, even anhydrous, 30% by weight aqueous being preferred, in essentially stoichiometric amount, although excess may be employed. The product may be recovered as the salt, e.g. by neutralisation and evaporation of water, or use may be made of the solution after filtering of solid catalyst.