A mixture of 10.0 g (0.051 mol) naphthalic anhydride, 3.9 g (0.056 mol) hydroxylamine hydrochloride and 80 ml pyridine was taken and stirred at 100 C for 10 hours. After cooling to room temperature, the reaction solution was poured into 1 N hydrochloric acid and the precipitate was recovered by filtration. The resulting precipitate 5.0 g was dissolved in pyridine (50 ml) into which 8.3 g (0.026 mol) of synthesized bis(pentafluoroethyl)phosphinic chloride was added dropwise while stirring at 0 C. After stirring at 25 C for 2 h, the reaction solution was extracted with dichloromethane-water, and the organic layer was removed under reduced pressure to remove the solvent, giving an orange solid. Recrystallization with acetonitrile gave a white solid 5.3 g, 0.01 mol). Bis(pentafluoroethyl)phosphinic chloride was added to trifluoromethanesulfonic acid and the anhydride (7.3 g, 0.028 mol) was substituted for the anhydride to give the crude product, N-hydroxynaphthimide trifluoromethanesulfonate (7.0 g, 0.020 mmol).
