Patent EP0161534A2 successfully refreshed from Google Patents.
EP0161534A2
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New process for the synthesis of pyrido-imidazo-refamycins
Assignee: Alfa Wasserman SpA
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Filing: 1985-04-19
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Granted: —
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Expires: 2005-04-19
Abstract
Abstract A new process for the synthesis of pyrido-imidazo-rifamycins of formula wherein R is hydrogen or acetyl, R, and R 2 independently represent hydrogen, (C 1-4 )-alkyl, benzyloxy, mono- or di-(C 1-3 )-alkylamino-(C 1-4 )-alkyl. (C 1-3 )-alkoxy-(C 1-4 )-alkyl, hydroxymethyl, hydroxy-(C 2 - 4 )-alkyl, cyano, halogen, nitro, mercapto, (C 1-4 )-alkylthio, phenylthio, carbamoyl, mono- or di-(C 1-4 )-alkyl-carbamoyl, or R 1 and R 2 taken together with two consecutive 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 0 of (Continuation next page) with a 2-aminopyridine of formula wherein R 1 and R 2 have the same meanings as before.
Inventors
- 👤 Vincenzo Cannata
- 👤 Gian Franco Tamagnone
- 👤 Silvano Piani
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 16:19
CPC Classifications
C; C07; C07D; C07D498/00; C07D498/22; A; A61; A61P; A61P31/00; A61P31/04
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
183 words
1) A new process for the preparation of pyrido-imidazo rifamycins of formula wherein R is hydrogen or acetyl, R 1 and R 2 independently represent hydrogen, (C 1-4 )-alkyl, benz y lox y , mono- or di-(C 1-3 )--alkylamino-(C 1-4 )-alkyl, (C 1-4 )-alkoxy-(C 1-4 )-alkyl, hydroxymethyl, hydroxy-(C 2-4 )-alkyl, cyano, halogen, nitro, mercapto, (C 1-4 )-alkylthio, phenylthio, carbamoyl, mono- or di-(C 1-4 ) -alkyl-carbamoyl, or R 1 and R 2 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, which comprises reacting a molar equivalent of rifamycin 0 of formula with from about 1 to about 9 molar equivalents of a 2-amino- pyridine of formula in the presence of a solvent or a solvent system, at a temperature comprised between about the room temperature and the boiling temperature of the reaction mixture, for a period of time comprised between about 10 and about 100 hours, optionally in presence of iodine or of a system iodide/oxidizing agent, and recovering the end products by means of known techniques.
Claim 2
Dependent Claim
183 words
1) A new process for the preparation of pyrido-imidazo rifamycins of formula wherein R is hydrogen or acetyl, R 1 and R 2 independently represent hydrogen, (C 1-4 )-alkyl, benz y lox y , mono- or di-(C 1-3 )--alkylamino-(C 1-4 )-alkyl, (C 1-4 )-alkoxy-(C 1-4 )-alkyl, hydroxymethyl, hydroxy-(C 2-4 )-alkyl, cyano, halogen, nitro, mercapto, (C 1-4 )-alkylthio, phenylthio, carbamoyl, mono- or di-(C 1-4 ) -alkyl-carbamoyl, or R 1 and R 2 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, which comprises reacting a molar equivalent of rifamycin 0 of formula with from about 1 to about 9 molar equivalents of a 2-amino- pyridine of formula in the presence of a solvent or a solvent system, at a temperature comprised between about the room temperature and the boiling temperature of the reaction mixture, for a period of time comprised between about 10 and about 100 hours, optionally in presence of iodine or of a system iodide/oxidizing agent, and recovering the end products by means of known techniques.
Claim 3
Dependent Claim
31 words
2) A process as defined in claim 1, wherein for each molar equivalent of rifamycin O, from about 2 to about 6 molar equivalents of 2-aminopyridine of formula III are used.
Claim 4
Dependent Claim
48 words
3) A process as defined in claim 1, wherein the solvent or solvent system is selected among lower halogenated hydrocarbons, lower alkanols, lower alkyl esters of lower aliphatic acids, acetonitrile, glycols, dioxane, tetrahydrofuran alone or in admixture among them or in admixture with water in different volumetric ratios.
Claim 5
Dependent Claim
34 words
4) A process as defined in claim 1, wherein, for each molar equivalent of rifamycin O, from about 0.1 to about 1 molar equivalents of iodine or of a system iodide/oxidizing agent is used.
References Cited (Backward Citations)
US4341785A
Cited
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