Solid acid catalysed synthesis of biologically potent quinazolinones: Environmentally benign approaches

Quinazolinones are fused nitrogen containing heterocyclic compounds that play an important role in the design of plethora of medicinal and biologically active molecules. Medicinal chemists have taken a keen interest in quinazolinones since this huge family of compounds exhibit a wide range of biological activities (e.g., antibacterial, antimalarial, anticonvulsant, anticancer, antileishmanial, anti-inflammatory, etc.). These compounds are both naturally occurring and synthetically produced. There have been several methods developed over the years for synthesizing the quinazolinone framework. As far as the synthesis of quinazolinone is concern, there are several issues such as multistep synthesis, severe reaction conditions, and the use of hazardous chemicals/solvents. Catalysis is one of the solutions to address these issues. Quinazolinone derivatives are generally obtained via both, homogeneous and heterogeneous catalysis. In general, the solid acid catalysts (heterogeneous catalysts) are most favoured over liquid acid catalysts (homogeneous catalysts) to avoid issues related to handling, isolation, regeneration, and disposal due to the corrosive and harmful nature of liquid acids. In this review, a brief account of the sustainable synthesis strategies of quinazolinone and its derivatives have been included. The strategies along with synthetic conditions including several solid acid catalysts such as silica-based solid acid catalysts, carbon nano tubes (CNTs), heteropoly acids (HPAs), zeolites, metal organic frameworks (MOFs), etc. to synthesise quinazolinone based molecules have been summarized. Furthermore, the biological and pharmacological properties of quinazolinone and its derivatives, along with their structure activity relationship (SAR) are discussed and reviewed in this review.