Microwave Assisted Synthesis of Biologically Active α-Aminophosphonates Catalyzed by Nano-BF₃·SiO₂ under Solvent-Free Conditions

Abstract

An efficient and high-yield synthesis of a class of new α-aminophosphonate derivatives as diethyl α-aryl/2-thienyl-α-[2-(phenylthio)phenylamino]methylphosphonates 6a–j in short reaction times from three component coupling reactions (Kabachnik-Fields reaction) of 2-aminodiphenylsulfide 3, substituted phenyl/heterocyclic aldehydes 4a–j, and diethyl phosphite 5 is reported. The reaction proceeds smoothly in the presence of the catalyst, nano-silica-supported boron trifluoride (BF₃·SiO₂) without using solvent under microwave irradiation. The title compounds were tested for in vitro antibacterial and antifungal activities at concentrations of 100 and 200 μg/disc. Minimum inhibitory concentrations (MICs) were also examined.

Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional text, figures and tables.

GRAPHICAL ABSTRACT

Keywords:

• Nano-silica-supported boron trifluoride (BF₃·SiO₂)
• microwave irradiation
• solvent-free conditions
• α-aminophosphonates
• antimicrobial activity
• minimum inhibitory concentrations (MICs)

Acknowledgments

The authors gratefully acknowledge financial support from University Grants Commission [UGC F.No. 40-71/2011 (SR)] under which this research was pursued, and for editing of the final manuscript by Jeanne Gilbert, USA.