Process for the preparation of 3-substituted thiophenes
US5512685A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 1994 |
| Grant date | Apr 30, 1996 |
| Priority date | — |
| Expiry date | Dec 20, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D333/08
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention relates to a process for the preparation of 3-substituted thiophenes in which the substituent is a C.sub.4 -C.sub.18 -alkyl group. According to the invention, the preparation is carried out by allowing an alkali metal salt of a C.sub.4 -C.sub.18 -alkyl-succinic acid to react with a compound of sulfur and phosphorus, e.g. tetraphosphorus decasulfide, in an organic solvent at a temperature of 100.degree.-180.degree. C., the product obtained being 3-(C.sub.4 -C.sub.18 -alkyl)thiophene. The said reaction may be the last step in a process in which the initial material is maleic acid anhydride with which .alpha.-C.sub.4 -C.sub.18 -alkene is combined so that C.sub.4 -C.sub.18 -alkenylsuccinic acid anhydride is obtained, whereafter this is hydrogenated catalytically to produce C.sub.4 -C.sub.18 -alkylsuccinic acid anhydride. This is thereafter reacted with an alkali metal hydroxide so that an alkali salt of the C.sub.4 -C.sub.18 -alkylsuccinic acid is obtained, which salt is reacted with a compound of sulfur and phosphorus to produce 3-(C.sub.4 -C.sub.18 -alkyl)thiophene, which constitutes the final product.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.