203808-43-9 3,4-Dihydro-3-butyl-5,6-dimethyl-2,4-dioxothieno(2,3-d)pyrimidine-1(2H)-acetic acid Thieno(2,3-d)pyrimidine-1(2H)-acetic acid, 3,4-dihydro-3-butyl-5,6-dimethyl-2,4-dioxo-