3-bromo-5-chloro-pyridines used as intermediates in the synthesis of azatetralones
US5436344A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 18, 1994 |
| Grant date | Jul 25, 1995 |
| Priority date | — |
| Expiry date | Mar 18, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/55
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Compounds of the formula ##STR1## wherein R.sup.1 is hydrogen, fluoro, chloro, bromo, nitro, trifluoromethyl, C.sub.1 to C.sub.4 alkoxy, C.sub.1 to C.sub.4 alkylthio or C.sub.1 to C.sub.6 alkyl and R.sup.2 is a group of the formula ##STR2## wherein R.sup.3 is hydrogen or C.sub.1 to C.sub.6 alkyl, R.sup.4 is --CH.dbd.C.sub.2, --CH.sub.2 --YR.sup.5, or --COR.sup.6, R.sup.5 is hydrogen or an acid labile alcohol protecting group, Y is oxygen or sulfur, and R.sup.6 is --NR.sup.7 R.sup.8 or --OR.sup.9 wherein R.sup.7, R.sup.8 and R.sup.9 are independently selected from hydrogen or C.sub.1 to C.sub.6 alkyl, or an alkaline or alkaline earth metal salt thereof, which are intermediates in the preparation of hydantoin aldose reductase inhibitors and methods of preparing these intermediates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.