Process for the preparation of 7-aminocephalosporanic acids
US3932392A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 1974 |
| Grant date | Jan 13, 1976 |
| Priority date | — |
| Expiry date | Jan 14, 1994 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D501/18
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
7-Aminocephalosporanic acid (7-ACA) and 7-amino-3-methyl-3-cephem-4-carboxylic acid (7-ADCA) are valuable intermediates in the preparation of semi-synthetic cephalosporins. These compounds are commonly prepared by cleaving the amide bond of compounds having the formula ##SPC1## In which R.sup.6 is H or ##EQU1## R is the side chain of a known penicillin, especially phenoxymethyl or benzyl, and the amino and carboxyl functions are blocked; by A. halogenating the blocked compounds Ia or IIa to produce an imino-halide; B. forming an imino-ether from the imino-halide by treatment with an alcohol; and C. mixing said imino-ether with water or an alcohol to produce 7-aminocephalosporanic acid or 7-amino-3-methyl-3-cephem-4-carboxylic acid. The invention claimed is the use of dicyclohexylamine or diisopropylamine instead of a tertiary amine acid scavenger in step A.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.