One-pot synthesis of diethyl 4,4′-(1,4-phenylene)bis-[6-(halomethyl)- 2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates] and their bispyrrolocyclization

A one-pot synthesis of diethyl 4,4′-(1,4-phenylene)bis[6- (chloromethyl)-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates] is proposed via three-component condensation of terephthalic aldehyde, 4-chloroacetoacetic ester, and ureas under Biginelli reaction conditions. Interaction of the obtained precursors that contain two highly reactive binucleophilic groups with primary amines leads to bis-heterocyclization with formation of (1,4-phenylene)-bis(pyrrolo[3,4-d]pyrimidine-2,5-diones).