Process for the preparation of 4-substituted-1,4-dihydropydrines
US5310917A · kind A · utility
7Cited by
3References
24Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 28, 1992 |
| Grant date | May 10, 1994 |
| Priority date | — |
| Expiry date | Jul 28, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D413/04
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
4-Substituted-1,4-dihydropyridines are prepared by a cycloaddition reaction in which the cyclization is driven to completion, after thermal reaction, by addition of an acid. Felodipine, a vasodilator, is prepared by a cycloaddition reaction of ethyl 3-aminocrotonate with a suitably substituted dichlorobenzylidine under reaction conditions whereby the product crystallizes out of the reaction solution and may be directly isolated by filtration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.