In this article, we report an efficient and mild synthetic route for the construction of substituted quinazolines from functionalized 2-aminobenzophenones with various benzaldehydes using cat. TMSOTf and hexamethyldisilazane (HMDS) under neat, metal-free and microwave irradiation conditions in which gaseous ammonia was formed in situ. This synthetic protocol provided the desired quinazolines with a broad substrate scope in good to excellent yields. Some structures were confirmed by X-ray single-crystal diffraction analysis.

This study describes an efficient protocol for the preparation of substituted 2,4-diaryl-3-sulfonylquinolines from functionalized 2-aminobenzophenones and aromatic β-ketosulfones by using p-toluenesulfonic acid monohydrate under microwave irradiation. In this atom-economical synthetic route, a series of pharmaceutically active 3-arylsulfonylquinolines with good functional group tolerance are prepared in good to excellent yields. Some structures are confirmed by single-crystal X-ray diffraction analysis.

Herein, we report a facile synthetic methodology for the preparation of 2,3-dialkylquinolines from anilines and propionaldehydes. This cyclization involved environmentally friendly Nafion^® NR50 as an acidic catalyst with microwave irradiation as the heating source. A series of substituted 2-ethyl-3-methylquinolines were prepared from various anilines and propionaldehyde derivatives through this protocol with good to excellent yields. Some new chemical structures were confirmed by X-ray single-crystal diffraction analysis and the related data were provided. The plausible reaction mechanism studies are also discussed.