3-Methylenecephalosporins and process for production thereof
US3932393A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 25, 1971 |
| Grant date | Jan 13, 1976 |
| Priority date | — |
| Expiry date | Feb 25, 1991 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/55
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
3-Methylenecepham-4-carboxylic acids and esters of the Formula I and 3-methyl-.DELTA..sup.3 -cephem-4-carboxylic acids and esters of the Formula II ##SPC1## where R is hydrogen or an organic acyl group and R.sub.1 is hydrogen, C.sub.1 -C.sub.4 alkyl a carboxylic acid protecting group or a pharmaceutically acceptable cation are prepared via the reductive displacement of a 3-substituted methyl cephalosporin of the Formula III ##SPC2## where R.sub.2 is an organic residue such that --SR.sub.2 constitutes a reductively displaceable moiety, and R and R.sub.1 have the same meanings as defined in Formulae I and II, reductive displacement being accomplished by catalytic hydrogenation or chemical reduction. The 3-methylene cepham compounds are isomerized in dimethylacetamide in the presence of a tertiary alkyl amine to provide 3-methyl-7-acylamido-.DELTA..sup.3 -cephem-4-carboxylic acids and esters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.