Efficient and Recyclable [EMIM]OAc Catalyzed Aqueous Synthesis of 2,3-Dihydroquinazolin-4(1H)-ones

Abstract

The present study describes a sustainable and efficient protocol for the synthesis of  quinazolinone derivatives using recyclable 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) as a green ionic liquid catalyst. The cyclocondensation of 2-aminobenzamide with various substituted benzaldehydes was successfully achieved in water at 80 °C, affording excellent yields under environmentally benign conditions. Systematic optimization of catalyst loading, temperature, and comparative catalytic performance established the optimal reaction conditions. The catalyst exhibited remarkable recyclability with minimal loss of activity over successive cycles, highlighting its robustness and practical applicability. A plausible mechanistic pathway has also been proposed to elucidate the catalytic role of [EMIM]OAc in promoting the transformation. The protocol offers a simple, high-yielding, and eco-friendly approach for the synthesis of diverse quinazolinone derivatives.