Ultrasound-based approach to spiro-2,3-dihydroquinazolin-4(1H)-ones: Their in vitro evaluation against chorismate mutase

Amberlyst-15 has been identified as a green and reusable catalyst in the synthesis of spiro 2,3-dihydroquinazolin-4(1H)-ones under ultrasound irradiation at room temperature. The reaction can be performed in an open flask as the conversion was found to be not sensitive to the presence of air or atmospheric moisture. The methodology was found to be general and a wide variety of spiro 2,3-dihydroquinazolin-4(1H)-ones were prepared from 2-aminobenzamides and cyclic ketones within a few minutes in quantitative yields. The products isolated do not require any chromatographic purification. This method provides advantages such as shorter reaction time, high yields of products, and simple operational procedures. Some of the compounds showed chorismate mutase inhibitory properties when tested in vitro.