Method for the preparation of substituted 1,4-dihydro-4-oxo-cinnoline-3-carboxylic acid, esters and salts thereof, and intermediates used in their preparation
US5183891A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Nov 9, 1989 |
| Grant date | Feb 2, 1993 |
| Priority date | — |
| Expiry date | Nov 9, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D237/28
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method for the preparation of compounds of the formula ##STR1## wherein X represents a group of the formula OR.sub.1 or NR.sub.1 R.sub.2, wherein R.sub.1 and R.sub.2 independently represent H or an organic group that forms a stable covalent bond with the N or O of said X; Y is H or an organic group that forms a stable ester with the adjacent COO group; R is an alkyl or aryl group optionally substituted with one or more stable organic substituents; each R.sub.3 independently represents a stable organic group; and n is an integer from 0 to 3; PA1 the method using new intermediates of the formula ##STR2## wherein R.sub.3 and Y have the foregoing meanings; W is either F or Cl; PA1 and R.sub.9 is a hydrocarbon such as a C.sub.1 -C.sub.4 alkyl or alkenyl group.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.