2-Mercapto-5-carbethoxyuracil 38026-46-9 5-Pyrimidinecarboxylic acid, 1,2,3,4-tetrahydro-4-oxo-2-thio-, ethyl ester 5-Pyrimidinecarboxylic acid, 1,2,3,4-tetrahydro-4-oxo-2-thioxo-, ethyl ester NSC1584