Isopropyl 6-methyl-4-phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate (en)5-pyrimidinecarboxylic Acid, 1,2,3,4-tetrahydro-6-methyl-4-phenyl-2-thioxo-, 1-methylethyl Ester (en)