A CONVENIENT SYNTHESIS OF SUBSTITUTED QUINAZOLIN-4(3H)-ONES UNDER MICROWAVE AND SOLVENT-FREE CONDITIONS

A clean and facile synthesis of the title compounds is achieved from cyclocondensation of 2-aminobenzamides with orthoesters catalyzed by SiO ₂ /H ₂ SO ₄ in dry and microwave conditions.     

Sulfuric Acid: A Mild Catalyst for the Regioselective Synthesis of 2-Substituted [1,2,4]Triazolo[5,1- b ][1,3]thiazin-7-ones

 A facile and regioselective synthesis of 2-substituted [1,2,4]triazolo[5,1-b][1,3]thiazin-7-ones by action of sulfuric acid on (4H-[1,2,4]triazol-3-ylsulfanyl)-acrylic acids is described.     

Pentafluorophenylammonium triflate (PFPAT): An efficient, metal-free and reusable catalyst for the von Pechmann reaction

Pentafluorophenylammonium triflate (PFPAT) is used as an efficient catalyst in the von Pechmann condensation of phenols with β-ketoesters leading to the formation of coumarin derivatives. Short reaction times, easy and quick isolation of the products, excellent chemoselectivity, excellent yields and ease of catalyst recovery with consistent activity makes this protocol efficient and environmentally benign.