Synthesis of 2, 3-dihydroquinazolin-4(1H)-ones promoted by an efficient, inexpensive and reusable heterogeneous Lewis acid catalyst

Heterogeneous catalysts have been widely used in industrial and green chemistry because of their unique advantages such as easy removal from the reaction media by simple filtration. In this work, the cross-linked poly (4-vinylpyridine) supported BF3, [P4-VP]-BF3, as an efficient, inexpensive and reusable heterogeneous Lewis acid catalyst was easily prepared and characterized by using FT-IR (ATR), EDX, FE-SEM and elements mapping techniques. Then, the obtained eco-friendly catalyst was used for preparation of 2, 3-dihydroquinazolin-4(1H)-ones in good to high yields via the one-pot reaction of anthranilamide with different aldehydes or ketones in ethanol at reflux conditions. This catalyst is inexpensive, efficient and easy to remove from the reaction mixture by a simple filtration and can be reused several times without losing its activity. The advantages of this methodology are, the easy purification of product, clean reaction media, simple workup, and separation of the catalyst by a filtration and reuse several times.