SiO₂–H₂SO₄ Nanoparticles: A Solid Phase Acidic Catalyst and an Efficient for One-Pot Synthesis of 3,9-Diamino-5,10-dioxo-1-aryl-5,10-dihydropyrazolo[1,2-b]phthalazine-2-carbonitrile Derivatives

Abstract

Nanostructured SiO₂–H₂SO₄ as an efficient and nano catalyst for one-pot synthesis of phtahalazines via three-component condensation of an aromatic or aliphatic aldehyde, malononitrile and 5-amino-2,3-dihydro-phthalazine-1,4-dione. Nanostructured SiO₂–H₂SO₄ was synthesized and characterized via FT-IR and SEM techniques. It is rapid and efficient catalyst for one-pot synthesis of the biologically important 3,9-diamino-5,10-dioxo-1-aryl-5,10-dihydropyrazolo[1,2-b]phthalazine-2-carbonitrile derivatives. The significant features of this methodology are nontoxic catalyst, short reaction time (10 min), recyclability, low catalyst loading, green organic solvent (ethanol), and avoiding tedious purification step.

Keywords:

• 5-amino-2,3-dihydro-phthalazine-1,4-dione
• aromatic aldehyde
• malononitrile
• multicomponent reaction
• nanoparticle silica-supported sulfuric acid
• pyrazolo[1,2-b]phthalazine-2-carbonitrile derivatives