Microwave-assisted synthesis and anti-inflammatory activity evaluation of some novel α-aminophosphonates

GRAPHICAL ABSTRACT

ABSTRACT

An expeditious green synthetic approach was developed for the synthesis of α-aminophosphonates in good yields through one-pot three component reaction (Kabachnik-Fields reaction) of equimolar quantities of N-(4-amino-2-phenoxy phenyl)methanesulfonamide, diethylphosphite and various aldehydes under conventional as well as microwave irradiation methods. The newly synthesized compounds were characterized by NMR (³¹P, ¹H, and ¹³C), Mass, IR and C, H, N analyses. The synthesized compounds were screened for their anti-inflammatory activity using rat paw edema method. Most of the compounds from the series showed good anti-inflammatory activity when compared with standard drug. Especially the compounds 5d bearing 4-hydroxy-3-nitrophenyl moiety, 5e bearing 3-bromo-4-fluorophenyl moiety, 5g incorporated with 2,4-dichlorophenyl moiety and 5f containing 4-chlorophenyl moiety exhibiting edema inhibition of 91.01% to 85.39% after 4 h of carrageenan injection while the other compounds displayed inhibition ≥75%.

KEYWORDS:

• α-Aminophosphonates
• Kabachnik-Fields reaction
• microwave irradiation
• anti-inflammatory activity

Acknowledgments

The authors acknowledge Dr. Sk. Adam, department of biochemistry, Sri Venkateswara University, Tirupathi, India, for providing biological activity. Also, the authors express their thanks to Hyderabad Central University for providing instrumentation facilities for recording the spectra.