A facile and an efficient method has been developed for the synthesis of novel α-aminophosphonates 4a-n by the one-pot three component reaction of equimolar quantities of 4-amino-N-2-thiazolyl-benzenesulfonamide (Sulfathiazole) (1), diethyl/dibutyl phosphites (2) and various aldehydes (3a-n) in dry toluene at reflux conditions via Kabachinik-Fields reaction in high yields (70-80%) in the presence of 1, 4-dimethylpiperazine as a new catalyst. Their chemical structures were established by IR, 1H, 13C, 31P-NMR, mass spectral studies and elemental analyses. All the title compounds exhibited promising antibacterial, antifungal and antioxidant activities.