3-Azino:methyl rifamycin SV derivs. prodn. - by reacting 3-formyl cpd. with amidrazone

摘要

Prodn. of azinorifamycins of formula (I) comprises reacting 3-formylrifamycin SV (III) in THF, dichloromethane or chloroform with an amidrazone NH2.N=CH.NR1R2 (II). In the formulae, Y is H or acetyl; R1 is 3-4C alkenyl or 1-7C alkyl; R2 is 7-8C aralkyl (opt. ring-substd. by one halo), phenyl, 3-6C ring cycloalkylalkyl, 3-7C cycloalkyl, 3-4C alkenyl, 2-4C alkenyl or 1-7C alkyl, or NR1R2 is a 5-8C ring (opt. substd. by 1 or 2 methyl) or morpholino) morpholino). Alternatively, (I) are made by reacting rifamycin S in the THF and in presence of MnO2 with azine CH2=N.N=CH.NR1R2 (IV). Cpds. (I) are described in GB applicn. no. 8134549.