l-Proline-accelerated, eco-friendly synthesis of 9-substituted-2,3,4,9-tetrahydro-1H-xanthen-1-ones under mild conditions

An efficient l-proline-accelerated synthesis of 9-substituted-2,3,4,9-tetrahydro-1H-xanthen-1-one derivatives has been accomplished via one-pot condensation of dimedone or 1,3-cyclohexanedione with substituted salicylaldehydes under mild reaction conditions. This protocol demonstrates several notable advantages, including operational simplicity, short reaction times, environmentally friendly conditions, no necessity of extraction and chromatographic purification steps, and high yields of the target products.

Graphical abstractAn efficient, environmentally benign and high yielding procedure has been developed for the synthesis of 9-substituted-2,3,4,9-tetrahydro-1H-xanthen-1-one derivatives via one-pot condensation of cyclic-1,3-hexanediones with salicylaldehydes in the presence of l-proline as an organocatalyst under mild reaction conditions.Figure optionsDownload full-size imageDownload as PowerPoint slide