Tandem Knoevenagel-[3+2] cycloaddition-elimination reactions: one-pot synthesis of 4,5-disubstituted 1,2,3-(NH)-triazoles

Sodium azide has been found to catalyse Knoevenagel condensation between aromatic aldehyde and cyano compound with active methylene hydrogens and this has led to a successful route for the one pot synthesis of 4,5-disubstituted 1,2,3-(NH)-triazoles from aldehydes through Knoevenagel-[3+2]cycloaddition-elimination sequence. In the formation of 5-aryl-2H-1,2,3-triazole-4-carbonitrile derivatives, the reaction has been found to occur efficiently in water.