Abstract A series of [2-acylamino-4, 5, 6, 7-tetrahydro-benzo [b] thienyl-(3)]-carboxamides with a basic group in the substituent at position 2 was cyclized by two methods to the corresponding substituted 2-alkyl-4-oxo-3, 4, 5, 6, 7, 8-hexahydro-benzo [b] thieno-[2, 3-d] pyrimidines. The starting materials were prepared by reaction of [2-chloracetylamino-4, 5, 6, 7-tetrahydro-benzo [b]-thienyl-(3)]-carboxamide with secondary amines or benzylamine.
![2-(2-morpholin-4-yl-acetylamino)-4,5,6,7-tetrahydro-benzo[b]thiophene-3-carboxylic acid amide Structure](https://image.chemsrc.com/caspic/166/20887-00-7.png)
![2-[(N-benzyl-glycyl)-amino]-4,5,6,7-tetrahydro-benzo[b]thiophene-3-carboxylic acid amide Structure](https://image.chemsrc.com/caspic/015/20886-93-5.png)
![2-[(benzylamino)methyl]-5,6,7,8-tetrahydro-3H-[1]benzothiolo[2,3-d]pyrimidin-4-one Structure](https://image.chemsrc.com/caspic/477/20886-94-6.png)