α-Haloacrylates as acceptors in the [3+2] cycloaddition reaction with NaN3: an expedient approach to N-unsubstituted 1,2,3-triazole-4-carboxylates

An expedient synthesis of N-unsubstituted 1,2,3-triazole-4-carboxylates has been demonstrated through [3 + 2] cycloaddition of sodium azide with alpha-haloacrylates. The process is highly reliable and exhibits an unusually wide scope with respect to alpha-fluoro-, alpha-chloro-, alpha-bromo-, and alpha-iodoacrylates. The potential of selected 1,2,3-triazole-4-carboxylates in the preparation of 1,5-dihydro-4H-[1,2,3]-triazolo-[4,5-c]-quinolin-4-one has also been illustrated.