One-pot, three-component synthesis of novel pyrano[3,2-c]coumarins containing sulfone moiety utilizing ultrasonic irradiation as eco-friendly energy source

Multi-component reaction of 4-hydroxy coumarin, aromatic aldehydes, and sulfone derivatives catalyzed by piperidine has been accomplished for the synthesis of a series of novel pyrano[3,2-c]coumarin derivatives in ethanol under ultrasonic irradiations. We provide a series of coumarin derivatives containing sulfone moiety of interest for biological screening tests. The reactions were carried out under both conventional and ultrasonic irradiation conditions. In general, improvement in rates and yields was observed when reactions were carried out under sonication compared with classical silent conditions. Structures of the products were established on analytical and spectral data.