[C:1]([C:4]1[CH:5]=[C:6]([CH:12]=[CH:13][N:14]=1)[C:7]([O:9][CH2:10][CH3:11])=[O:8])(=[O:3])[NH2:2].[ClH:15]>CO.[Pt](=O)=O>[ClH:15].[C:1]([CH:4]1[CH2:5][CH:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])[CH2:12][CH2:13][NH:14]1)(=[O:3])[NH2:2]Ethyl 2-carbamoylisonicotinate (4.24 g, 21.83 mmol) was slurried in MeOH (50 mL) and HCl in MeOH (17.47 mL, 21.83 mmol) and platinum(IV) oxide (0.248 g, 1.09 mmol) were added. The mixture was hydrogenated at 5 bar in a Büchi hydrogenation apparatus. After 3 h there were still starting material left. platinum(IV) oxide (0.14 g, 0.62 mmol) was added and the reaction continued for 2 h when platinum(IV) oxide (0.387 g, 1.70 mmol) was added and the reaction was stirred overnight. The reaction mixture was filtered and evaporated to give ethyl 2-carbamoylpiperidine-4-carboxylate hydrochloride (3.93 g, 90%). 1H NMR (400 MHz, dmso) δ 1.16 (t, 3H), 1.31-1.63 (m, 2H), 1.86 (d, 1H), 2.26 (d, 1H), 2.54-2.66 (m, 1H), 2.74-2.88 (m, 1H), 3.10-3.19 (m, 1H), 3.47-3.56 (m, 1H), 4.06 (q, 2H), 7.38 (s, 1H), 7.71 (s, 1H). MS m/z 201 (M+H)+
Wird geladen…
