CA1218650A — Process for the synthesis of pyrido-imidazo- rifamycins
Assigned to Alfa Farmaceutici SpA · Expires 1987-03-03 · 39y expired
What this patent protects
ABSTRACT OF THE DISCLOSURE A new process for the synthesis of pyrido-imidazo-rifamycins of formula I wherein R is hydrogen or acetyl, R1 and R2 independently repre-sent hydrogen, (C1-4)-alkyl, benzyloxy, mono- or di-(C1-3)-alkylamino-(C1-4)-alkyl, (C1-3)-alk…
USPTO Abstract
ABSTRACT OF THE DISCLOSURE A new process for the synthesis of pyrido-imidazo-rifamycins of formula I wherein R is hydrogen or acetyl, R1 and R2 independently repre-sent hydrogen, (C1-4)-alkyl, benzyloxy, mono- or di-(C1-3)-alkylamino-(C1-4)-alkyl, (C1-3)-alkoxy-(C1-4)-alkyl, hydroxymethyl, hydroxy-(C2-4)-alkyl, cyano, halogen, nitro, mer-capto, (C1-4)-alkylthio, phenylthio, carbamoyl, mono- or di-(C1-4)-alkyl-carbamoyl, or R1 and R2 taken together with two consecu-tive carbon atoms of the pyridine nucleus form a benzene ring optionally substituted by one or two methyl or ethyl groups. The process comprises reacting the rifamycin B of formula II with a 2-aminopyridine of formula III wherein R1 and R2 have the same meanings as before, in presence of a suitable oxidizing agent.
Drugs covered by this patent
- Xifaxan (rifaximin) · Bausch Health
Bibliographic data sourced from FDA Orange Book + USPTO public records. Plain-English summary generated by AI grounded in source text. Patent term extensions (PTR, SPC, pediatric) may shift the effective expiry. Not legal advice.
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