[F:1][C:2]1[CH:3]=[C:4]([C:13]2[CH:14]=[C:15]([CH:20]=[CH:21][N:22]=2)[C:16]([O:18][CH3:19])=[O:17])[CH:5]=[C:6]([F:12])[C:7]=1[C:8]([F:11])([F:10])[F:9].[ClH:23]>CO.[Pt](=O)=O>[ClH:23].[F:12][C:6]1[CH:5]=[C:4]([CH:13]2[CH2:14][CH:15]([C:16]([O:18][CH3:19])=[O:17])[CH2:20][CH2:21][NH:22]2)[CH:3]=[C:2]([F:1])[C:7]=1[C:8]([F:11])([F:9])[F:10]Methyl 2-(3,5-difluoro-4-(trifluoromethyl)phenyl)isonicotinate (3.147 g, 9.92 mmol) was dissolved in MeOH (20 mL) and hydrogen chloride (1.25 M in MeOH, 23.81 mL, 29.76 mmol) was added. The reaction was stirred at room temperature for 2 h and evaporated. Methanol (20 mL) and platinum(IV) oxide (0.113 g, 0.50 mmol) was added and the solution hydrogenated in a Büchi hydrogenator at 5 bar and room temperature for 4.5 h. Platinum(IV) oxide (0.113 g, 0.50 mmol) was added and hydrogenation continued for 4 h. The catalyst was filtered off and washed with MeOH. The filtrate was evaporated in vacuo to yield methyl 2-(3,5-difluoro-4-(trifluoromethyl)phenyl)piperidine-4-carboxylate hydrochloride (3.12 g, 87%) as a white solid. MS m/z 324 (M+H)+
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