Intermediates useful in the preparation of 3,4-dihydro-4-oxothieno[2,3-d]pyrimidine-2-carboxylates and process for preparing same
US4701528A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1985 |
| Grant date | Oct 20, 1987 |
| Priority date | — |
| Expiry date | Dec 23, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D495/04
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
There are disclosed compounds of Formulas I and II: ##STR1## wherein R.sup.1 and R.sup.2 may be hydrogen, lower alkyl having from 1 to 8 carbon atoms, lower alkenyl having from 3 to 6 carbon atoms, lower alkoxy having from 1 to 6 carbon atoms, hydroxy, nitro, amino, halo including chlorine, bromine, iodine, and fluorine, phenyl, alkanoyl having from 2 to 6 carbon atoms or they are bonded to one another to form a cycloalkene ring fused to the thiophene ring and having a total of from 5 to 7 annular ring carbon atoms, and R.sup.3 is an aliphatic or an aromatic group such as lower alkyl, e.g., methyl or ethyl. Such compounds are useful as intermediates in the production of tiprinast and related compounds. There is also disclosed a process for the regioselective synthesis of a compound of Formula I wherein R.sup.1 is CH.sub.3 and R.sup.2 is (CH.sub.3).sub.2 CHCH.sub.2 which comprises reacting a mixture of compounds of the following formulas: ##STR2## and ##STR3## with trichloroacetonitrile under acidic conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.