Fe(HSO4)3/SiO2: An efficient and heterogeneous catalyst for cyclization of 2- aminochalcones to 2- aryl-2,3- dihydroquinolin- 4(1H)- ones

Silica ferric hydrogensulfate is an efficient heterogeneous catalyst for the cyclization of 2- aminochalcones to the corresponding 2,3-dihydroquinolin- 4(1H)-ones. This intramolecular aza Michael reaction was carried out in high yields using chalcones bearing of electron donating and electron withdrawing groups. The catalyst is reusable without significant decreases in its activity after four times recycling.The present study represents the application of silica supported ferric hydrogensulfate as catalyst for the aza-Michael cyclization of 2-aminochalcones to the corresponding 2-aryl-2,3-dihydroquinolone derivatives. Therefore, the simplicity of the procedure, the mildness of the reaction conditions, high yields, the ease of catalyst separation and its re-usability demonstrates the ability of this method.