Reactions of vinyl azides and β-haloalkyl azides with active methylene compounds. Synthesis of 1-vinyl-1,2,3-triazoles

A general synthetic approach to the yet unknown class of 1-vinyl-1,2,3-triazoles is the condensation of active methylene compounds with vinyl azides or their precursors, the β-haloalkyl azides, in the presence of an alkoxide. Triazole-4-carboxylic acids prepared in this manner are decarboxylated smoothly on heating above their melting point. The use of NMR spectra in the structure assignment of some of the triazoles is discussed.