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