[N+:1]([C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[NH:9][CH:8]=[C:7]2[C:13]1[CH2:18][CH2:17][C:16](=O)[CH2:15][CH:14]=1)([O-:3])=[O:2].CC(O)=O.Cl.[CH3:25][NH2:26].[OH-].[Na+]>ClCCCl>[CH3:25][NH:26][CH:16]1[CH2:17][CH2:18][C:13]([C:7]2[C:6]3[C:10](=[CH:11][CH:12]=[C:4]([N+:1]([O-:3])=[O:2])[CH:5]=3)[NH:9][CH:8]=2)=[CH:14][CH2:15]1
A solution of compound 79 (0.07 g, 0.273 mmol) in 1,2-dichloroethane (3 mL) was treated with AcOH (0.015 mL, 0.273 mmol), methylamine hydrochloride (0.018 g, 0.273 mmol), NaBH(OAC)3 (0.086 g, 0.409 mmol) at room temperature and stirred for over night (14 h). The reaction was basified with 2 N NaOH (25 mL) and product was extracted into ethyl acetate (2×20 mL). The combined ethyl acetate layer was washed with brine (15 mL) and dried (Na2SO4). Solvent was evaporated and crude was purified by column chromatography (2 M NH3 in methanol: CH2Cl2, 1:9) to obtain compound 80 (0.074 g, quantitative) as a solid. mp 208-210° C.; 1H NMR (DMSO-d6) δ 1.44-1.53 (m, 1H), 1.97-2.01 (m, 2H), 2.35 (s, 3H), 2.40-2.57 (m, 3H), 2.60-2.70 (m, 1H), 6.13 (brs, 1H), 7.54 (d, 1H, J=9.0 Hz), 7.63 (s, 1H), 8.00 (d, 1H, J=7.5 Hz), 8.67 (s, 1H), 11.85 (brs, 1H); ESI-MS m/z (%): 272 (M+, 100).
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