4-Azidotetrahydroquinazoline derivatives in CuAAC reaction

4-Azido-2-methyltetrahydroquinazoline N-oxide cleanly undergoes the copper(i)-catalyzed azide–alkyne cycloaddition (CuAAC) reaction with alkynes to give new conjugates with pyrimidine N-oxide and triazole moieties. Its deoxygenated analogue, 4-azido-2-methyltetrahydroquinazoline, is inert in CuACC process due to the shift of imidoyl azide–tetrazole equilibrium towards the tetrazole tautomer.