Synthesis and analgesic activity of some novel 2-substituted 1,3,4-thiadiazolo

An ecofriendly synthesis for 1,2,3,4,5,6,8-octahydro- 3-amino-2-thioxo-benzothieno[2,3-d]pyrimidin-4-one (7A, B) has been developed. A series of hitherto unreported compounds (2a-i, 3a-c) have been synthesized by treating 3-Amino-2-mercaptopyrimidinones (7A, B) with one carbon donors like chloroacetyl chloride or chloroacetic acid and subsequently replacing the chloro group by various nucleophiles. Compound 2f was successfully synthesized by an alternate route. All the new compounds were characterized by elemental and spectral analyses. They were screened for analgesic activity in mice. Compounds 2a, b, 3a, b, and 2e, showed very good activity.