Synthesis of 2,2′-dipyrryl ketones from pyrrole-2-carboxylic acids with trifluoroacetic anhydride

Abstract

An efficient synthesis of 2,2′-dipyrryl ketones has been carried out from pyrrole-2-carboxylic acids using trifluoroacetic anhydride (TFAA). Simultaneous generation of both mixed anhydride and 2-unsubstituted pyrrole, via facile decarboxylation with in-situ generated TFA, made their cross reaction (intermolecular Friedel-Crafts acylation) possible and efficient.