| 摘要 |
A process for the synthesis of imidazo rifamycins of formula wherein R is hydrogen or acetyl, R1 and R2 independently represent hydrogen, (C1-4)-alkyl, benzyloxy, mono- or di-(C1-3)- -alkylamino-(C1-4)-alkyl, (C1-3)-alkoxy-(C1-4)-alkyl, hydroxy -(C1-4)-alkyl, cyano, halogen, nitro, mercapto, (C1-4)-alkylthio, phenylthio, carbamoyl, mono- or di-(C1-4)-alkyl-carbamoyl, or R1 and R2 taken together with two consecutive carbon atoms of the pyridine nucleus form a benzene ring optionally substituted by 1 or 2 methyl or ethyl groups. The process comprises reacting the rifamycin S of formula II with a 2-aminopyridine of formula III wherein R1 and R2 have the above seen meanings. |
