Improved Method for the Synthesis of 1‐Vinylindole

A highly efficient method has been developed for the synthesis of 1-vinylindole based on the vinylation of indole by acetylene at atmospheric pressure using the superbase KOH–DMSO catalytic system. The method allows the preparation of the 1-vinylindole in 94% yield with a purity of 99% (after a single distillation of the crude product).