Process for the preparation of thiophenes
US4252976A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 1978 |
| Grant date | Feb 24, 1981 |
| Priority date | — |
| Expiry date | Jul 21, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D333/24
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the preparation of 3-substituted thiophenes which involves cyclization of a novel intermediate, avoids the use of previously employed expensive starting materials. The thiophenes are useful for the preparation of penicillins and cephalosporins. The process is for the preparation of a thiophene of formula (I): ##STR1## where R.sup.1 represents a carboxylic acid group, or an ester or amide thereof or a nitrile group; R.sup.2 represents a group suitable for use as an .alpha.-substituent in the side-chain of a penicillin or cephalosporin; which comprises treating a compound of formula (II): ##STR2## wherein X represents halogen or optionally functionalized hydroxyl, Y represents halogen, hydroxyl, or alkoxy; with a source of nucleophilic sulphur under basic conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.