PREPARATION OF 2 - AMINO - 5 - METHYL - PYRIDINE AND THE 2 - DIALKYLAMINO - 5 - METHYL - PYRIDINE INTERMEDIATES

摘要

Process for the preparation of 2-amino-5-methyl-pyridine of the formula CH3 H2NN characterised in that in a first step, 3-methyl-pyridine 1-oxide of the formula CH3 NO Q is reacted with a trialkylamine of the formula R3N in which R represents alkyl, and with an acid chloride or acid anhydride, in the presence or absence of a diluent, to give the ammonium salt of the formula CH3(IV) ZQ R3NN in which ZQ represents an anion formed from an acid chloride or acid anhydride, the compound (IV) is, possibly, isolated as a crude intermediate and, possibly, further purified and then in a second step (a) either the ammonium salt of the formula (IV) is reacted with hydrogen bromide, in the presence or absence of a diluent, at temperatures between 150]C and 300]C, (b) or alternatively an alkyl compound RZ is cleaved by conventional methods from the compound (IV) and the 2-dialkylamino-5-methyl-pyridine formed during this of the formula CH3 R2NN(V) is reacted with hydrogen bromide, in the presence or absence of a diluent, at temperatures between 150]C and 300]C.