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.