2-Butenedioic acid, (E)-, 2-(1,2,3,4-tetrahydro-5-methyl-2,4-dioxo-3-propynyl-1-pyrimidinyl)-, diethyl ester Fumaric acid, 2-(1,2,3,4-tetrahydro-5-methyl-2,4-dioxo-3-propynyl-1-pyrimidinyl)-, diethyl ester NSC693986 Pyrimidine-2,4(1H,3H)-dione, 1-[1,2-bis(ethoxycarbonyl)ethenyl]-5-methyl-3-propynyl-, (E)-, Thymine, 1-[1,2-bis(ethoxycarbonyl)ethenyl]- 3-propynyl-, (E)-