Synthesis, spectral characterization and bioassay of 3,3′-(1,4-phenylene)-bis[2-alkoxycarbonyl-alkyl)-2-thio-benzoxa-phosphinines]

Synthesis of 3,3′-(1,4-phenylene)-bis[2-alkoxycarbonyl-alkyl)-2-thio-benzoxaphos-phinines] ( 3a– j) were accomplished via two step process. It involves the prior preparation of monochloride intermediate ( 2) and its subsequent reaction with the amino acid esters in dry tetrahydrofuran-toluene in the presence of triethylamine at reflux temperature. These compounds were characterized by IR, 1H, 13C, 31P NMR and were found to exhibit potent in vitro antioxidant activity. A new series of 3,3′-(1,4-phenylene)-bis[2-alkoxycarbonyl-alkyl)-2-thio-benzoxaphos-phinines] ( 3a– j) have been designed, synthesized and evaluated for antioxidant properties. 3f, 3g and 3j exhibited high antioxidant property [Display omitted]