Synthesis of methyl esters of 5-aroyl-6-aryl-2-oxo-1,2,3,6-tetra-hydropyrimidine-4-carboxylic acids

Methyl esters of 5-aroyl-6-aryl-2-oxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acids were synthesized from three component mixtures of methyl esters of aroylpyruvic acids, urea, and substituted benzaldehydes. 8-Hydroxy-4,5-diphenyl-3,4-dihydropyrimido[4,5-d]pyridazin-2(1H)-one was synthesized by the reaction of 5-benzoyl-2-oxo-6-phenyl-1,2,3,6-tetrahydropyrimidin-4-carboxylate with hydrazine hydrate.