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.