Synthesis of tetrahydrobenzimidazo[1,2-b]quinazolin-1(2H)-one and tetrahydro-1,2,4-triazolo[5,1-b]quinazolin-8(4H)-one ring systems under solvent-free conditions.

Tetraheterocyclic benzimidazo[1,2-a]quinazolin-4(1H)-one and tetrahydro-1,2,4-triazolo[5,1-b]quinazolin-8(4H)-one were synthesized in relatively high yields by the condensation reaction of an aldehyde and a cyclic beta-diketone with 2-aminobenzothiazole, 2-aminobenzimidazole or 3-amino-1,2,4-triazole without using any catalyst under solvent-free conditions.