Synthesis of xanthene and coumarin derivatives in water by using β-Cyclodextrin

Abstract

Simple and green procedure was developed for the synthesis of various xanthene and coumarin derivatives using beta-cyclodextrin (β-CD) as reusable catalyst at 70 °C in water. Condensation of salicylaldehyde (1 mmol) and dimedone (2 mmol) or 1,3 cyclohexadione (2 mmol) gave corresponding xanthene derivatives, while condensation of salicylaldehyde (1 mmol) with Meldrum’s acid (1 mmol) or 4-Hydroxy-6-methyl-2H-pyran-2-one (1 mmol) gave respective coumarin derivatives in impressive yields. Involvement of β-CD as catalyst was ascertained by inclusion complex evaluation of β-CD-salicylaldehyde with 1H NMR analysis at 70 °C.