Process for preparing N,O-dialkylhydroxylamine, its salts or intermediates in their synthesis

A process for preparing N,O-dialkylhydroxycarbamic acid ester which comprises reacting hydroxylamine or its salt with dihydrocarbyl carbonate in the presence of a basic compound to prepare hydroxycarbamic acid ester and subsequently alkylating this compound with an alkylating agent; a process for recovering N,O-dialkylhydroxycarbamic acid ester which comprises azeotropically distilling the ester with water from a solution containing the ester; a process for preparing N,O-dialkylhydroxylamine which comprises hydrolyzing N,O-dialkylhydroxycarbamic acid ester in an aqueous solution or a hydrous solvent in the presence of an alkali; a process for purifying N,O-dialkylhydroxylamine hydrochloride which comprises adding aldehyde or ketone to a solution of N,O-dialkylhydroxylamine hydrochloride containing O-alkylhydroxylamine hydrochloride as impurities to convert the O-alkylhydroxylamine hydrochloride into O-alkyl aldoxime or O-alkyl ketoxime and subsequently separating the N,O-dialkylhydroxylamine hydrochloride from the reaction system; and a process for separating N,O-dialkylhydroxylamine hydrochloride which comprises (i) adding benzene or alkylated benzene to an aqueous solution containing N,O-dialkylhydroxylamine hydrochloride, azeotropically removing water or a hydrochloride solution, and, subsequently (ii)adding alcohol thereto to obtain N,O-dialkylhydroxylamine hydrochloride in the form of crystal.