N-Hydroxyfluorobenzimidoylphosphonates and their O-acyl derivatives are synthesized. Reaction of phosphorylated oximes with sulfinyl chloride proceeds with rearrangement and leads to synthetically prospective N-sulfonylimidoylphosphonates. By the method of F-19 NMR are revealed values of sigma-constants of N-hydroxy- and N-acyloxy substituted imidoylphosphonate groups.