A series of novel pyrazole amides J 1 -J 15 containing an a-aminophosphonate moiety were synthesized and subsequently characterized by spectral (IR, F-NMR) data and elemental analysis. The racemic sample of J 1 was further separated into its enantiomers under normal-phase condition on two immobilized polysaccharide-based chiral stationary phases (Chiralpak IA and Chiralpak IC). The synthesized compounds revealed certain degree of antiviral activity in the bioassay. The title compounds (J 3 , J 10 , and J 12 ) showed some curative activities (39.9%, 41.8%, 50.1%, respectively) against tobacco mosaic virus at 0.5 mg/mL.