Synthesis of Azaheterocycles by Microwave-Assisted Activation of N-Acylarylamines

Significance

The synthesis of fused azaheterocycles by treatment of N-acylarylamines with 2-chloropyridine and trifluoroacetic anhydride followed by reaction with different nucleophilic agents is described. The proposed mechanism involves Tf₂O-assisted 2-chloropyridinium adduct formation which then undergoes annulation by reaction with respective nucleophiles. The advantage of the microwave technique is clearly demonstrated in several cases of comparison with conventional heating conditions.