[BH4-].[Na+].C[O:4][C:5](=O)[C@@H:6]([NH:15][C:16]([C:18]1[CH:26]=[C:25]2[C:21]([CH:22]=[N:23][N:24]2[CH2:27][CH:28]([CH3:30])[CH3:29])=[CH:20][C:19]=1[O:31][C:32]1[CH:37]=[CH:36][C:35]([F:38])=[CH:34][C:33]=1[F:39])=[O:17])[CH2:7][CH2:8][N:9]1[CH2:14][CH2:13][CH2:12][CH2:11][CH2:10]1>CO>[OH:4][CH2:5][C@@H:6]([NH:15][C:16]([C:18]1[CH:26]=[C:25]2[C:21]([CH:22]=[N:23][N:24]2[CH2:27][CH:28]([CH3:30])[CH3:29])=[CH:20][C:19]=1[O:31][C:32]1[CH:37]=[CH:36][C:35]([F:38])=[CH:34][C:33]=1[F:39])=[O:17])[CH2:7][CH2:8][N:9]1[CH2:14][CH2:13][CH2:12][CH2:11][CH2:10]1Sodium borohydride (0.012 g, 0.31 mmol) was added portion-wise to a heated (50° C.) solution of (S)-2-{[5-(2,4-difluorophenoxy)-1-isobutyl-1H-indazole-6-carbonyl]-amino}-4-piperidin-1-yl-butyric acid methyl ester (0.022 g, 0.042 mmol) in MeOH. The reaction mixture was stirred at 50° C. until HPLC analysis showed consumption of the starting material. The mixture was cooled to room temperature and concentrated under reduced pressure. The residue was diluted with ethyl acetate and 1N HCl. The organics were extracted with 1N HCl until the organic layer contained no product by HPLC analysis. The aqueous solution was basified to pH 14 with NaOH and then extracted with dichloromethane several times. The combined organics were dried over MgSO4 and concentrated under reduced pressure to afford 9.1 mg of oil (44% yield). MS (APCI+) m/z 501 (M+1) detected.
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