2,4-dioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylic acid 5-pyrimidinecarboxylic acid, 1,2,3,4-tetrahydro-2,4-dioxo- InChI=1/C5H4N2O4/c8-3-2(4(9)10)1-6-5(11)7-3/h1H,(H,9,10)(H2,6,7,8,11