Process for preparing benzaldoximes

摘要

It is described a process for preparing benzaldoximes of the formula (XV), in which X means NO2, S(O)nRy; Rx, Ry are in each case any inter radical; m is 0, 1, 2, 3 or 4; n is 0, 1 or 2; which comprises the converting of compounds of the formula (XVI), in which X and (Rx)m are as defined above with an organic nitrite of the formula R-O-NO, wherein R is an aliphatic or aromatic radical, in the presence of a base, the reaction being carried out at a temperature below -20 °C, in the presence of a dipolar aprotic solvent followed, if appropriate, by conversion of the oxime group -CH=NOH in formula (XV) into the corresponding aldehydes -CHO, nitriles (-CN) or nitrile oxides (-CNO).