Preparation of 3-4-2: [3-Fluoro-4-(Boc-piperazinyl)]aniline
To 150 mL of ethyl acetate were sequentially added 9.3 g (28.6 mmol) of tert-butyl 4-(2-fluoro-4-nitrophenyl)piperazine-1-carboxylate synthesized by the preparation of Example 3-4-1 and 930 mg (10 wt%) of Pd/C catalyst. The mixture was placed in a hydrogen reactor and reacted at 4 bar hydrogen pressure for 6 hours. Upon completion of the reaction, the Pd/C catalyst was removed by filtration. The filtrate was concentrated by distillation under reduced pressure and subsequently dried under vacuum at about 40 °C to give 8.22 g (yield: 97%) of the title compound.
Mass spectrum (M + H)+: 296.11
1H-NMR (DMSO-d6) δ: 1.42 (s, 9H), 2.76 (br m, 4H), 3.43 (br m, 4H), 5.02 (s, 2H), 6.33 (m, 2H), 6.79 (m, 1H).
