Expedient Strategy for the Synthesis of 5-Acylethynylpyrrole-2-carbaldehydes

Abstract5-Acylethynylpyrrole-2-carbaldehydes have been synthesized from the protected pyrrole-2-carbaldehydes by their transition-metal-free topochemical mechanoactivated ethynylation with acylbromoacetylenes in a solid Al2O3 medium (room temperature, 6 h, 41–54% yields).