Abstract 3-Substituted thieno [2, 3-d] pyrimidin-4 (3H)-one-2-mercaptoacetic acids and their ethyl esters were synthesized from 2-mercaptothieno [2, 3-d] pyrimidin-4 (3H)-ones, which were obtained by cyclization of thienylthioureas in acidic medium. Analgesic, anti- inflammatory, and anticonvulsant activities were found in some of these compounds. Significant antimicrobial activity was exhibited by thienylthioureas.
![2-methyl-2,3,6,7,8,9-hexahydro-benzo[4,5]thieno[2,3-d]thiazolo[3,2-a]pyrimidin-5-one Structure](https://image.chemsrc.com/caspic/451/52881-31-9.png)
![(3-METHYL-4-OXO-3,4,5,6,7,8-HEXAHYDRO-BENZO-[4,5]THIENO[2,3-D]PYRIMIDIN-2-YLSULFANYL)ACETIC ACID Structure](https://image.chemsrc.com/caspic/381/59898-74-7.png)
![ethyl 2-(phenylcarbamothioylamino)-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene-3-carboxylate Structure](https://image.chemsrc.com/caspic/344/132605-17-5.png)
![2-MERCAPTO-3-PHENYL-3,5,6,7,8,9-HEXAHYDRO-10-THIA-1,3-DIAZA-BENZO[A]AZULEN-4-ONE Structure](https://image.chemsrc.com/caspic/495/59898-71-4.png)
![3-BENZYL-2-MERCAPTO-5,6-DIMETHYL-3H-THIENO[2,3-D]PYRIMIDIN-4-ONE Structure](https://image.chemsrc.com/caspic/126/59898-63-4.png)