Process for preparing thiazolobenzimidazoles and intermediates used therein
US4812574A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Dec 23, 1987 |
| Grant date | Mar 14, 1989 |
| Priority date | — |
| Expiry date | Dec 23, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D513/14
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention concerns a process for preparing a thiazolo[3,2-a]benzimidazole of formula I ##STR1## in which formula n is 1 or 2, and R.sub.1 is hydrogen, lower alkyl, lower alkoxy, trifluoromethyl or halo, or a salt thereof which comprises dehydrating a compound of formula II, ##STR2## or a salt thereof wherein n and R, are as defined above, and COOR is an acid or ester function in the presence of an acid selected from sulphuric, sulphonic and phosphoric acid or mixtures thereof and if desired or required an inert solvent provided that if water is present then the amount of water is less than about 15% by volume of the acid, the reaction being carried out with heating if necessary.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.