A Convenient One-pot Method For The Synthesis Of 2-aryl-quinazuolines

Many quinazoline derivatives have widespread applications because of their biological activity. Quinazoline derivatives are important constituents of biologically active natural products and provide a backbone for designing pharmacologically useful drugs and functional organic materials. Although many methods for preparing 2-arylquinazolines are available, the reported procedures either require multi-step preparations from special reagents/reactants or suffer severe limitation such as tedious experimental procedure and very poor yields. Therefore a new alternative route for the synthesis of 2-arylquinazolines needs to be explored. In this work, a novel, one-pot procedure for synthesizing a variety of quinazoline derivatives has been developed. 2-Aryl-1,2,3,4-tetrahydroquinazolines, which were prepared by condensation of 2-aminobenzylamine and aromatic aldehydes, were oxidezed with MnO2 to form the quinazolines..By screening the reaction conditions such as solvents, oxidants etc., an optimized reaction condition for construction 2-Aryl-quinazolines was obtained. The results indicated that activited manganese dioxide was an effective oxidant for the transformation from 2-Aryl-1,2,3,4-tetrahydroquinazolines to the corresponding 2-Aryl-quinazolines. Good yield were achieved when 2-aminobenzylamines reacted with aromatic aldehydes which contain electron-withdraw or weak electron-donating substituent groups. Since this synthesis procedure has many merits such as readily available reagents, high yields, mild reaction conditions, extremely simple purification procedures, this method should provide quick access to 2-Aryl-quinazolines in industrialization.