摘要:
A process for preparing an N,O-dialkylhydroxycarbamic acid ester, which comprises reacting hydroxylamine or a salt thereof with a dihydrocarbyl carbonate in the presence of a base to prepare hydroxycarbamic acid ester, and subsequently alkylating this compound with an alkylating agent; a process for recovering an N,O-dialkylhydroxycarbamic acid ester, which comprises azeotropically distilling the ester with water from a solution containing the ester; a process for preparing an N,O-dialkylhydroxylamine, which comprises hydrolyzing an N,O-dialkylhydroxycarbamic acid ester in an aqueous solvent in the presence of an alkali ; a process for purifying an N,O-dialkylhydroxylamine hydrochloride, which comprises adding an aldehyde or a ketone to a solution of an N,O-dialkylhydroxylamine hydrochloride containing an O-alkylhydroxylamine hydrochloride as an impurity to convert the O-alkylhydroxylamine hydrochloride into O-alkyl aldoxime or O-alkyl ketoxime, and subsequently separating the N,O-dialkylhydroxylamine hydroxhloride from the reaction system ; and a process for separating a N,O-dialkylhydroxylamine hydrochloride, which comprises (i) adding benzene or alkylated benzene to an aqueous solution containing the N,O-dialkylhydroxylamine hydrochloride, azeotropically removing water or a hydrochloride solution, and subsequently (ii) adding an alcohol to obtain the N,O-dialkylhydroxylamine hydrochloride in crystal form.
steht, worin R₃ Niederalkyl, Hydroxyniederalkyl, Niederalkoxyniederalkyl, Carboxy, Niederalkoxycarbonyl, Phenyl, durch Niederalkyl, Halogenniederalkyl, Hydroxyniederalkyl, Halogen, Hydroxy, Niederalkoxy, Niederalkanoyloxy und/oder Nitro substituiertes Phenyl, Pyridyl, durch Niederalkyl, Hydroxyniederalkyl, Niederalkoxyniederalkyl, Phosphonooxyniederalkyl, Niederalkanoyl, Carboxy, Niederalkoxycarbonyl, Hydroxy, Niederalkoxy, Niederalkanoyloxy, Nitro und/oder Oxido substituiertes Pyridyl oder Chinolyl bedeutet, R₄ für Wasserstoff, Niederalkyl, Hydroxyniederalkyl oder Halogenniederalkyl steht oder R₃ und R₄ zusammen C₄-C₆-Alkylen oder Benzo-C₄-C₆-alkylen bedeuten, und R₂ geradkettiges C₁-C₄-Alkyl bedeutet, und Salze davon haben eine starke spezifische Hemmwirkung auf das Enzym Ornithindecarboxylase. Die Verbindungen der Formel I werden nach an sich bekannten Verfahren hergestellt.
摘要:
By reacting 3,3,4,4-tetrafluoro-2-(trifluoromethyl)-1,2-oxazetidine (I) with a Lewis acid, in particular SbF₅ or AsF₅, the fluorinated compounds (II), (III) and (IV) are obtained: