Cyclocondensation of Anthranilamide with Aldehydes on Gallium-Containing MCM-22 Zeolite Materials.

A gallium-containing MCM-22 (Mobil Composition of Matter No. 22) zeolite material was prepared using a simple hydrothermal method. Fourier transform infrared spectroscopy analysis and powder X-ray diffraction provide evidence of the formation of a pure MCM-22 phase framework and an MWW (MCM-tWenty-tWo) structure. Scanning electron microscopy images showed a uniform spherical shape, interpenetrating the platelet structure and a uniform particle size of approximately 6 μm. Ga nuclear magnetic resonance studies confirmed the presence of gallium in both the tetrahedral framework and the octahedral extra-framework environment. From the sorption studies, the presence of strong acidic sites and the microporous nature of the material were evident. The resultant Ga-MCM-22 material showed an excellent isolated yield of 95% in the synthesis of 2,3-dihydroquinazolin-4(1)-ones by cyclocondensation of anthranilamide with aldehydes in ethanol. The scope of the reaction was further explored by employing various cyclic, aromatic, and aliphatic aldehydes with anthranilamide. The results provide a very good yield (85-95%). A significant advantage of the developed protocol includes high yield, use of a green solvent, and easy removal of the catalyst through filtration within a short reaction time.