Pham Duy Quang Dao, Chan Sik Cho*, Son Long Ho and Ho-Sang Sohn Pages 85 - 93 ( 9 )
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 and pyrazole).
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 starting compounds.
Benzimidazole, β-bromo-α, β-unsaturated amide, copper powder, imidazole, pyrazole, pyrimidinone.
Department of Applied Chemistry, Kyungpook National University, Daegu 702-701, Department of Applied Chemistry, Kyungpook National University, Daegu 702-701, Department of Applied Chemistry, Kyungpook National University, Daegu 702-701, Department of Materials Science and Metallurgical Engineering, Kyungpook National University, Daegu 702-701