Synthesis of ethyl 2-((4-phenyl-1H-1,2,3-triazol-1-yl)methyl)-4H/2H-chromene- 3-carboxylates by cycloaddition of ethyl 2-(azidomethyl)-4H-chromene-3- carboxylates with alkynes

Abstract

The cycloaddition reaction of ethyl 2-(azidomethyl)-4H-chromene-3-carboxylates with phenylacetylene/ 4-fluorophenylacetylene have provided a mixture of 2H- and 4H-triazolylchromene-3-carboxylates. 4-Methoxyphenylacetylene, 3-methylphenylacetylene and acetylenedicarboxylates have provided exclusively 2H-triazolylchromene-3-carboxylates. Interestingly, prop-2-yn-1-ol and ethyl propiolate have provided exclusively 4H-triazolylchromene-3-carboxylates.