Coumarins Preparation by Pechmann Reaction Under Ultrasound Irradiation. Synthesis of Hymecromone as Insecticide Intermediate

Hymecromone, an important insecticide intermediate, were synthesized under solvent-free conditions by Pechmann reaction upon ultrasound irradiation in the presence of acid zeolites possessing different structural features. This methodology offers significant improvements for the synthesis of coumarins with regards to yield of product, simplicity in operation, and avoiding toxic catalysts and solvents.