Green and Convenient Synthesis of Pharmaceutically Active Mono and Bis-dihydroquinazolines via a One-pot Multicomponent Reaction Under Sulfamic Acid Catalysis

Introduction Multicomponent reactions (MCRs) and green chemistry are essential criteria for the development of efficient chemical syntheses for valuable organic compounds. Methods The design, synthesis, and development of sustainable procedures for the production of novel biological and pharmaceutical molecules have gained high importance. Herein, an environmentally benign synthesis of mono- and bis-2,3-dihydroquinazolin-4(1H)-ones as pharmaceutically active compounds was carried out in good to high yields of 80-99% within 45-120 minutes. Results The desired products were synthesized via three-component and pseudo five-component condensations of isatoic anhydride, a primary amine (aniline or ammonium acetate), and an aldehyde/dialdehyde using sulfamic acid (20%) as a solid acidic catalyst under the solvent-free condition at 100degree celsius. Conclusion The easy work-up procedure, metal-free and environmentally benign catalyst, green reaction conditions for performing MCRs, and high yields of pure products are some advantages of the presented protocol.