Heterocyclization of functionalized heterocumulenes with C,N-, C,O-, and C,S-Binucleophiles: XI. Synthesis of dialkyl 2-oxo-3,6-diaryl-1,2,3,6-tetrahydropyrimidine-4,5-dicarboxylates by cyclocondensation of 1-chlorobenzyl isocyanates with dialkyl anilinofumarates

1-Chlorobenzyl isocyanates react with N-arylfumarates with the formation of dialkyl 2-oxo-3,6-diaryl-1,2,3,6-tetrahydropyrimidine-4,5-dicarboxylates that on alkaline hydrolysis are converted into 6-alkoxycarbonyl-1,4-diaryl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylic acids. The condensation of 1-chloro-1-phenyl-2,2,2-trifluoroethyl isocyanate with N-arylfumarates results in dialkyl 6-oxo-2,3-diaryl-2-trifluoromethyl-1,2,3,6-tetrahydropyrimidine-4,5-dicarboxylates.