Synthesis of Xanthenediones by Silica Supported Orthophosphoric Acid (H3PO4·SiO2)

The novel protocol was developed for the synthesis of xanthenediones by silica supported orthophosphoric acid (H3PO4•SiO2) as a heterogeneous catalyst.The reported protocol is simple, scalable, mild and effective for the synthesis of xanthenediones.The (H3PO4•SiO2) catalyst demonstrated excellent catalytic activity for various substituted aromatic aldehydes.This catalyst can be reused four times without much loss in catalytic activity.