Process for the synthesis of oxazolopyridine compounds
US5077408A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 1990 |
| Grant date | Dec 31, 1991 |
| Priority date | — |
| Expiry date | Sep 17, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D498/04
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Process for the synthesis of compounds of formula (I): ##STR1## their pyridinium salts and N-oxides, in which formula: the nitrogen of the pyridine ring is situated in the .alpha.-, .beta.-, .gamma.- or .delta.-position with respect to the ring junction; PA1 R.sup.1 represents a halogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkoxy or a nitro, substituted or unsubstituted amino, phenyl or cyano group; PA1 0.ltoreq.m.ltoreq.2; PA1 R.sup.2 represents a lower alkyl or cycloalkyl group, a 5- or 6-membered heterocycle containing 1 or 2 hetero atoms, substituted or otherwise, or an aryl group ##STR2## such that: R.sup.3 represents a halogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkoxy or a nitro, phenyl, substituted or unsubstituted sulfonyl, cyano, thioalkyl, substituted or unsubstituted amino, substituted or unsubstituted sulfinyl, mercapto, hydroxyl or ester group, PA1 0.ltoreq.n.ltoreq.5 employing trimethylsilyl polyphosphate (PPSE) as a cyclization agent and enabling the compounds of formula (I) to be obtained in virtually quantitative yields. The compounds of formula I have anti-inflammatory, analgesic, and antipyretic …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.