An synthesis of tetrahydrobenzimidazo[2,1‑b]quinazolin‑1(2H)‑one using a new ionic Brönsted acid catalyst

Multi-component reactions (MCRs) are powerful tools in modernmedicinal chemistry, enabling straightforward access to large libraries of structurally related, drug-like compounds and thereby facilitating lead generation. Hence, combined with the use of combinatorial chemistry and high throughput parallel synthesis, such reactions have instituted an ncreasingly valuable approach to drug discovery efforts in recent years1. Quinazolinone derivatives have many biological activities such as analgesic, anti-inflammatory, antipyretic, antimicrobial, anticonvulsant, fungicidal, antidepressant and antitumor compounds2,3. In this work a newly reported ionic Brönsted acid catalystis used as an efficient and reusable catalyst in the synthesis of tetrahydrobenzimidazo[2,1-b]quinazolin-1(2H)-ones.The salient advantages of this method are mild reaction conditions, nontoxic and inexpensive catalyst, environmentally benign, high to excellent yields, shorter reaction times(figure 1).