Pyrimidine-2,4,6(1H,3H,5H)-trione (trivial name barbituric acid) and derivatives:
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(keto tautomeric form)
Salts of barbituric acid and its derivatives.
Source: PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1322 (https://doi.org/10.1351/pac199567081307)