Synthesis of quinazolinone derivatives using 2-amino benzamides and aldehydes under ball-milling conditions

2,3-Dihydroquinazolinone derivatives are an important class of fused heterocycles due to the broad range of potential biological activities [1]. The most popular method for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones is based on the condensation of aromatic aldehydes and 2-aminobenzamide catalyzed by NH4Cl,p-TSA and some other Lewis and Bronsted acids [2]. Most of these methods have certain limitations such as long reaction times, harsh reaction conditions, application of volatile organic solvents, toxic reagents and low yields of products. Recently, ball-milling has emerged as a powerful tool for effecting a chemical reaction in greener way [3]. In the present work, we report a new practical protocol for the synthesis of 2,3- dihydroquinazolin-4(1H)-ones by a simple One-Pot reaction of aldehydes and 2- aminobenzamide using heterogeneous acid catalysts under ball-milling conditions in the absence of solvents(figure 1). This method was applied to various aromatic aldehydes and the corresponding products achieved in good yields. All the products were characterized by 1H and 13C NMR spectra, melting point and comparison with authentic samples.