[CH2:1]([O:3][C:4]([C@H:6]1[CH2:11][CH2:10][C@H:9]([NH:12][NH:13]C(OC(C)(C)C)=O)[CH2:8][C@H:7]1[CH3:21])=[O:5])[CH3:2].[ClH:22].O1CCOCC1.C1C=C2C(C(O)(O)C(=O)C2=CC=1)=O>CCO.CCCCCC.CCOC(C)=O>[ClH:22].[NH:12]([C@H:9]1[CH2:10][CH2:11][C@H:6]([C:4]([O:3][CH2:1][CH3:2])=[O:5])[C@H:7]([CH3:21])[CH2:8]1)[NH2:13]To a 250-mL round-bottomed flask was added tert-butyl 2-((1S,3R,4S)-4-(ethoxycarbonyl)-3-methylcyclohexyl)hydrazinecarboxylate (5.089 g, 16.94 mmol) in EtOH (56.5 ml). Then hydrogen chloride, 4.0 M solution in 1,4-dioxane (72.0 ml, 288 mmol) was added into the reaction mixture. The overall mixture was allowed to stir under inert atmosphere overnight. The progress of the reaction was monitored by TLC (30% EtOAc in hexane; ninhydrin stain), which suggested reaction completion. The mixture was concentrated in-vacuo. The residue was diluted with hexane and concentrated in-vacuo. This gave (1S,2R,4S)-ethyl 4-hydrazinyl-2-methylcyclohexanecarboxylate hydrochloride (4.60 g) as white solid. This material was carried into the next step of the synthesis, without further purification. LCMS (ESI) m/z 201.2 (M+H)+.
Wird geladen…
