[CH2:1]([O:8][CH2:9][N:10]1[C:18]2[C:17]([O:19][CH3:20])=[N:16][CH:15]=[N:14][C:13]=2[C:12]([CH2:21][NH:22][C@H:23]([C@H:29]([OH:35])[C:30](OCC)=[O:31])[C:24](OCC)=[O:25])=[CH:11]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[BH4-].[Li+]>C(OCC)C.CO>[CH2:1]([O:8][CH2:9][N:10]1[C:18]2[C:17]([O:19][CH3:20])=[N:16][CH:15]=[N:14][C:13]=2[C:12]([CH2:21][NH:22][C@@H:23]([CH2:24][OH:25])[C@H:29]([OH:35])[CH2:30][OH:31])=[CH:11]1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1To a stirred solution of the product from Example 15.1 (0.166 g, 0.34 mmol) in diethyl ether (10 ml) was added methanol (0.14 ml, 3.41 mmol) and then lithium borohydride (0.85 ml, 1.71 mmol, 2.0M in THF). After 30 mins the reaction mixture was diluted with methanol and then concentrated. The residue was dissolved in methanol, diluted with concentrated aqueous ammonia (1 ml) and evaporated on to silica gel. The material was chromatographed on silica gel (DCM-methanol-conc. ammonia, 85:15:2, then 70:30:2, then 50:50:4). This gave three distinct compounds; firstly the title compound and then two different salt forms of the title compound. The three compounds were combined to give a colourless oil (0.103 g, 75%). 1H NMR (CD3OD) δ 8.42 (s, 1H), 7.64 (s, 1H), 7.28-7.16 (m, 5H), 5.75 (s, 2H), 4.50 (s, 2H), 4.10 (s, 3H), 3.83-3.68 (m, 3H), 3.63 (d, J=5.5 Hz, 2H), 3.31 (pentet, J=1.6 Hz, 1H).
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