Solvent-free sonochemical kabachnic-fields reaction to synthesize some new α-aminophosphonates catalyzed by nano-BF₃•SiO₂

GRAPHICAL ABSTRACT

ABSTRACT

To obtain a rapid, efficient synthesis of some new α-aminophosphonates, ultrasonic irradiation has been applied to the reaction mixtures containing amine, aromatic or heteroaromatic aldehydes and triethyl phosphite. The Kabachnik-Fields reaction was performed by using nano-BF₃•SiO₂ as a recyclable catalyst under solvent free conditions. Key advantages of this procedure consist in the eco-friendly and highly efficient reaction conditions, high yields, an easy work-up procedure, short reaction times and solvent free conditions. All title compounds were characterized by spectral and elemental analysis. They were further screened for their in vitro antioxidant activity by the DPPH, O²⁻ and NO methods. The majority of the title compounds showed good antioxidant activity when compared with the standard antioxidants.

KEYWORDS:

• α-aminophosphonates
• ultrasonic irradiation
• nano-BF₃•SiO₂
• antioxidant activity

Acknowledgments

The authors acknowledge Dr. Sk. Adam, Department of Biochemistry, Sri Venkateswara University, Tirupathi, India, for providing the measurements of the biological activities. The authors express their thanks to Hyderabad Central University for providing instrumentation facilities for recording the spectra.