One-pot multi-component synthesis of octahydroquinazolinone derivatives via Biginelli condensation using ZnCr2O4 nanoparticles as an efficient catalyst

In recent years, the Biginelli reaction has been employed for the synthesis of octahydroquinazolinones, which used cyclic β-diketones instead of open-chain dicarbonyl compounds using concentrated H2SO4 and HCl as the catalyst. These octahydroquinazolinone derivatives have attracted considerable attention owing to their diverse pharmacological properties [1,2]. The quinazolinone moiety is found, as alterative in a wide variety of biologically active compounds which can be used as hypnotic/sedative drugs for treatment of cancer. Furthermore, quinazolinone derivatives are of interest because they exhibit a broad spectrum of biological properties, such as analgesic, antiinflammatory, antimicrobial and anti-tubercular, anti-HIV, antimalarial and antihistamine [3,4]. ZnCr2O4 nanoparticle has been shown to be an inexpensive, efficient and mild catalyst for the one-pot synthesis of octahydroquinazolinone derivatives using dimedone, urea and appropriate aromatic aldehydes in ethanol as a solvent under reflux condition (scheme 1). This methodology is of interest due to the use of ethanol as a solvent without use of any organic solvent and toxic metals as catalyst, thus minimizing the cost, the operational hazards, and environmental pollution. Also this modified route provides much higher yields and simple work-up procedure of products.