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

<p>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 <i>N</i>-(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 <b>5d</b> bearing 4-hydroxy-3-nitrophenyl moiety, <b>5e</b> bearing 3-bromo-4-fluorophenyl moiety, <b>5g</b> incorporated with 2,4-dichlorophenyl moiety and <b>5f</b> 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%.</p

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

<p>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 <i>in vitro</i> 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.</p