Ultrasound-promoted synthesis of 4(3H)-quinazolines under Yb(OTf)3 catalysis

Abstract

A novel method to perform the Niementowski reaction leading to 4(3H)-quinazolines is reported. The 4(3H)-quinazolines were obtained in good to excellent yields by microwave irradiation or ultrasound-assisted synthesis from 2-aminobenzonitrile and acyl chlorides in solvent-free conditions and in the presence of Yb(OTf)3 (10 mol%). Ultrasound-based methodology performed better than the microwave-assisted process in terms of yields for all examples. The procedure reported herein represents also the first reported example of an ultrasound-promoted Niementowski-like reaction. (Chemical Equation Presented).