Benzyl 3N-difluorocyclopentylcarbamate (1.5 g, 5.88 mmol) was used as a raw material, which was dissolved in 6N HCl (6 mL) and the reaction was heated at 100 °C for 20 hours. After completion of the reaction, the mixture was cooled to room temperature and the brown solution was extracted with ether (2 x 2 mL) to remove unreacted feedstock and toluene. The aqueous phase was dried over vacuum heat to afford 3,3-difluorocyclopentylamine hydrochloride as a light brown solid (0.79 g, 85% yield). The structure of the product was confirmed by the following characterization data: 1H NMR (MeOD-d4, 400 MHz) δ: 4.79 (m, 1H), 2.62 (m, 1H), 2.32 (m, 2H), 2.18 (m, 2H), 1.87 (m, 1H); 13C NMR (MeOD-d4, 400 MHz) δ: 131.4 (t), 41.0 (t), 34.8 (t), 28.9; 19F NMR (MeOD-d4, standard CFCl3, 400 MHz) δ: -93.0 (m, 2F).LC/MS analysis showed the [M + H]+ peak was located at 121.9.
