Synonyms: Acetic acid, 2-[(3,4-dihydro-5,6-dimethyl-4-oxothieno[2,3-d]pyrimidin-2-yl)thio]-, ethyl ester;acetic acid, 2-[(4-hydroxy-5,6-dimethylthieno[2,3-d]pyrimidin-2-yl)thio]-, ethyl ester;Ethyl [(5,6-dimethyl-4-oxo-3,4-dihydrothieno[2,3-d]pyrimidin-2-yl)sulfanyl]acetate