A new application of polymer supported, homogeneous and reusable catalyst PEG-SO3H in the synthesis of coumarin and uracil fused pyrrole derivatives

A highly efficient, simple and convenient synthetic protocol for the synthesis of coumarin and uracil fused pyrrole derivatives has been demonstrated. A biodegradable, polymer supported catalyst, PEG-SO3H, was applied for the two component coupling of 4-aminocoumarin or 6-aminouracil and alpha,beta-unsaturated nitroalkene. The catalyst has efficiently catalyzed the Michael addition and intramolecular cyclisation with the concomitant removal of the nitro group. The catalyst was recycled for five cycles with almost unaltered catalytic activity.