Synthesis of medicinally important quinazolines decorated with 1,4-disubstituted-1,2,3-triazoles using CuSO4 center dot 5H(2)O-Et3N catalytic system

The direct use of Cu(II) sulfate pentahydrate in the presence of triethylamine afforded 1,4-disubstituted1,2,3-triazoles via 1,3-dipolar cycloaddition of terminal alkyne(s) to azide(s) at room temperature. A study on the additive effect of triethylamine in the presence of Cu(II) sulfate pentahydrate revealed that it is essential for the activation of the copper catalyst and is responsible for the reaction between aliphatic/aromatic heterocyclic alkyne(s) and azide(s), which otherwise did not react under the standard reaction conditions that are often used in click chemistry.