Synonyms: [1]Benzothieno[2,3-d]pyrimidine-3(4H)-acetic acid, 5,6,7,8-tetrahydro-4-oxo-, ethyl ester;Ethyl (4-oxo-5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidin-3(4H)-yl)acetate;ethyl 2-[4-oxo-5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidin-3(4H)-yl]acetate