Synthesis of novel 1,2,3-triazole compounds from coumarin derivatives

Coumarins are heterocyclic oxygen compounds formed by the fusion of a benzene nucleus with a pyran-2-one ring, this nucleus being an important pharmacophore found in biologically active compounds [1]. The literature reports various synthetic tools for the preparation of coumarin and its derivatives, including Knoevenagel, Pechmann condensation, Perkin, Reformatsky reactions, Wittig and Claisen arrangement [2]. 1,2,3-triazole is another heterocyclic class with important pharmacological properties, that occupies a prominent place in drug discoveries, due to its easy synthesis through click chemistry reaction, copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC), between alkynes and azides [3]. In the present work we describe the synthesis of novel coumarin derivatives (Scheme 1). The arylcoumarins 1 were prepared by Perkin reaction using ortho-hydroxybenzaldehyde substituted with 4-(hydroxyphenyl) acetic acid. Alkynes 2 were obtained from reaction between compound 1 and propargyl bromide. Compounds 3 were prepared by click chemistry reaction among alkynes 2 and phenyl azides substituted.