[Cl:1][C:2]1[C:3]([C:21]([F:24])([F:23])[F:22])=[C:4]([C:8]2[CH2:13][CH2:12][N:11]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[CH2:10][CH:9]=2)[CH:5]=[CH:6][CH:7]=1.C(O)(=O)C>[Pt]=O.C(OCC)(=O)C>[Cl:1][C:2]1[C:3]([C:21]([F:24])([F:22])[F:23])=[C:4]([CH:8]2[CH2:9][CH2:10][N:11]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[CH2:12][CH2:13]2)[CH:5]=[CH:6][CH:7]=1A mixture of tert-butyl 4-(3-chloro-2-(trifluoromethyl)phenyl)-5,6-dihydropyridine-1(2H)-carboxylate (0.438 g, 1.21 mmol), platinum oxide (0.082 g, 0.363 mmol), acetic acid (0.073 g, 1.21 mmol), and ethyl acetate (20 mL) was hydrogenated using a balloon for 20 h and filtered. The material was re-submitted to hydrogenation at 80° C. for 16 h and filtered. After concentration, the residue was chromatographed over silica gel (0-30% EtOAc in hexanes) to give tert-butyl 4-(3-chloro-2-(trifluoromethyl)phenyl)piperidine-1-carboxylate as colorless thick oil (0.115 g, 26%): 1H NMR (300 MHz, CDCl3) δ7.42-7.30 (m, 3H), 4.25 (br, 2H), 3.21 (m, 1H), 2.81 (m, 2H), 1.80-1.60 (m, 4H), 1.49 (s, 9H); MS (ESI+) m/z 308 [M+H]+.
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