1,4,Dihydro-pyridine intermediates
US5216157A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 17, 1991 |
| Grant date | Jun 1, 1993 |
| Priority date | — |
| Expiry date | Apr 17, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C251/24
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention relates to a process for the preparation of dimethyl-1,4-dihydro-2,6-dimethyl-4-(2'-nitro-phenyl)-pyridine-3,5-dicarbo xylate of the Formula I ##STR1## which comprises a) reacting a compound of the general Formula II ##STR2## (wherein n is 1 or 3; if n is 1, then R stands for a group of the Formula (a) ##STR3## and if n is 3, then R represents hydrogen) with methyl acetoacetate of the Formula III EQU CH.sub.3 --CO--CH.sub.2 --COOCH.sub.3 (III) PA1 and optionally with an amino compound of the general Formula IV ##STR4## (wherein Z is a group of the Formula (c), ##STR5## k is 1 and both symbols p are 0; or Z stands for a C.sub.1-5 straight or branched chain alkanoyloxy group or a carbonate, hydrocarbonate or hydroxy anion, k is 1 and both symbols p are 1; or k is 0, one of both symbols p is 0 and the other is 1) in an inert solvent; or PA1 b) reacting 2-nitro-benzaldehyde and methyl acetoacetate of the Formula III and aqueous ammonium hydroxide in the presence of an inert solvent in one step, at a temperature of 101.degree.-120.degree. C., under a pressure of 2.0-6.0 bar.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.