Silica-supported Sodium Hydrogen Sulfate and Amberlyst-15 : Two Efficient Heterogeneous Catalysts for Single-step Synthesis of 4(3H)-Quinazolinones from Anthranilic Acid, Ortho Esters, and Amines under Solvent Free Conditions

The single step synthesis of 4(3H)-quinazolinones has been carried out efficiently by coupling of the three components, anthranilic acid, ortho esters, and amines in the presence of silica-supported sodium hydrogen sulfate (NaHSO4·SiO2) or Amberlyst-15 as a heterogeneous catalyst. The reaction occurred within a few minutes under solvent free conditions to afford the products in excellent yields. One of the catalysts, Amberlyst-15 can be recovered and recycled.