OICC Press Iranian Journal of Catalysis 2345-4865 4 2 2024 02 03 Synthesis of 4,4´-(Arylmethylene)bis(1H-pyrazol-5-ols) catalyzed by nanosilica supported perchloric acid in water EN Bahareh Sadeghi Department of Chemistry, Central Tehran Branch, Islamic Azad University, Tehran, Iran Maryam Ghorbani Rad Department of Chemistry, Yazd Branch, Islamic Azad University, P.O. Box 89195-155, Yazd, Iran. Journal Article 2024 02 03 Reaction between aromatic aldehydes and 3–methyl-1-phenyl-2-pyrazoline-5-one catalyzed by nano-SiO2/HClO4 in water under reflux provided a simple and efficient route for the synthesis of 4-((5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)(aryl)methyl)-3-methyl-1-phenyl-1H-pyrazol-5-ol derivatives in high yields.