One-pot Synthesis of a New Category of 2-aryl-quinazolinones Using OImDSA as an Efficient Heterocyclic Medium.

Background: Dihydroquinazolinone derivatives are an important family of fused heterocyclic compounds which possess a wide range of biological, medicinal and pharmacological properties such as anti-tumor, anti-biotic, diuretic, analgesic, anti-hypertonic, anti-pyretic, antidepressant, anti-histamine and vasodilation activities.

Introduction: So far, some acid catalysts, e.g. p-toluenesulfonic acid, silica sulfuric acid, zinc(II) perfluorooctanoate, gallium(III) triflate, ionic liquid, Al(H2PO4)3, I2, montmorillonite K-10, Amberlyst-15, Al/Al2O3 and Fe3O4 nanoparticles, have been reported to accomplish this threecomponent reaction. Some of these methods have drawbacks such as toxic solvents and catalysts, long reaction time, the use of expensive catalysts and adverse yields.

Methods: A mixture of benzaldehydes (1mmol), isatoic anhydride (1 mmol), Glycine (1 mmol) and OImDSA (2 mL) were stirred at room temperature for the required reaction times (1-2 h). The progress of the reaction was monitored by TLC (EtOAc: petroleum ether 1:2). After completion of the reaction, as indicated by TLC, the ionic liquid was separated by extraction with 2×15 mL of water. The solid residue was separated by recrystallization from EtOH. The pure products were collected in 86-97% yields.

Results: Herein, we report the mild synthesis of some derivatives of 2-aryl-quinazolin-4(1H)-ones from isatoic anhydride and Glycine using OImDSA, which has been found to be an efficient synthesis method, with depleted side effects, reduced reaction steps, increased efficiency and curtailed reaction time, in continuation of our research on the synthesis of heterocyclic and pharmaceutical compounds.

Conclusion: In conclusion, we have developed a simple, green and efficient protocol for the synthesis of 2-aryl-quinazolin-4(1H)-ones using OImDSA. Simplicity, easy practice, inexpensive, environmentally friendly and reusable ionic liquid are notable attributes of this new method. To the best of our knowledge, this is the first report on the synthesis of a new library of quinazolin-4(1H)- ones derived from Glycine as a natural substrate based on green chemistry conditions.