Abstract A preparative method for the synthesis of diethyl 1-diazo-2, 2, 2- trifluoroethylphosphonate from trifluoroacetic anhydride and benzyl carbamate via diethyl 1- benzyloxycarbonylimino-2, 2, 2-trifluoroethylphosphonate is developed. Optimum conditions for the chlorination of benzyl N-trifluoroacetylcarbamate with SOCl 2—Py to afford the imidoyl chloride, phosphorylation of the latter under the conditions of the Arbuzov reaction, ...