Silica sulfuric acid, an efficient and recyclable solid acid catalyst for the synthesis of 4,4'-(arylmethylene)bis (1h-pyrazol-5-ols)

Article abstract of DOI:10.1080/00397911.2010.502999

Silica sulfuric acid (SSA) is employed as a recyclable catalyst for the condensation reaction of aromatic aldehydes with 3-methyl-l-phenyl-5-pyrazolone. This condensation reaction is performed in a mixture (1:1v/v) of water-ethanol at 70C, giving 4,4'-alk