Abstract The title substances 1 and 2 were prepared by acylation of the corresponding ethyl 2-amino-thiophene-(or:-4, 5, 6, 7-tetrahydro-benzo [b] thiophene)-3-carboxylates, in some cases followed by reactions introducing a basic substituent. Additionally a group of 2- aroylamino-thiophene-(or:-4, 5, 6, 7-tetrahydro-benzo [b] thiophene)-3-carboxamides was subjected to ring closure reactions, yielding the corresponding 2-aryl-thieno [2, 3-d] ...
![2-(4-methoxyphenyl)-3H-thieno[2,3-d]pyrimidin-4-one Structure](https://image.chemsrc.com/caspic/133/60442-56-0.png)
![2-(4-methoxyphenyl)-5,6-dimethyl-3H-thieno[2,3-d]pyrimidin-4-one Structure](https://image.chemsrc.com/caspic/095/60442-57-1.png)