Silica sulfuric acid as mild and efficient catalyst for the preparation of poly-hydroxyl aromatic compounds under mild and heterogeneous conditions.

A simple, clean and highly efficient method for the preparation of polyhydroxyl aromatic compounds is described from the reaction of 2,6-bis(methylol)phenols and different substituted phenols in the presence of silica sulfuric acid (SSA) as a heterogeneous catalyst. SSA afforded the clean synthesis of target compounds in much higher yields than traditional catalysts. The established method is also suitable for the synthesis of phloroglucinol derivatives (Phloroglucides) and other polyhydric phenols. Besides the easy work-up of the reaction mixture, the comfortable purification of the products is another advantage of this method.