4-(2-Ethylthio-5,6-dimethyl-4-oxo-3,4-dihydro-thieno/2,3-d/ pyrimidin-3-yl)benzoic acid, ethyl ester AIDS-140302 AIDS140302 Ethyl 4-(2-(ethylthio)-5,6-dimethyl-4-oxothieno[2,3-d]pyrimidin-3(4H)-yl)benzoate NSC651729