Background: Azole-fused pyrimidinones have been synthesized and tested for
biological activities. The present copper-catalyzed version will be attempted as an alternative
synthetic method for such N-fused hybrid structures.
Objective: This research aims to develop a new synthetic method of azole-fused
pyrimidinones from β-bromo-α,β-unsaturated amides and azoles (benzimidazole, imidazole
Method: β-Bromo-α,β-unsaturated amides react with azoles in DMF at 100°C for 1 h in the
presence of a catalytic amount of copper powder and base under microwave irradiation.
Result: β-Bromo-α,β-unsaturated amides are coupled and cyclized with azoles to give the corresponding azolefused
pyrimidinones in moderate to good yields via tandem intermolecular C-N coupling and C-N formative cyclization
by C-H activation.
Conclusion: This work provides a new method for synthesizing N-fused hybrid scaffolds such as benzimidazo[
1,2-a]pyrimidin-2-ones, imidazo[1,2-a]pyrimidinones and pyrazolo[1,5-a]pyrimidinones from readily available