Active methylene building block CAS 769-42-6

1,3-Dimethylbarbituric acid (CAS 769-42-6) is a N,N-disubstituted barbituric acid derivative​ and a highly versatile active methylene building block. Its core is a six-membered 1,3-diazinane-2,4,6-trione ring in which the two ring nitrogens are methylated, leaving a single reactive methine (C5) position between two carbonyls.This structural feature makes it a predictable, regioselective nucleophile​ for carbon-carbon bond formation, while avoiding the complications of N-H tautomerism and N-alkylation side reactions seen with the parent barbituric acid.