C[O:2][C:3](=[O:32])[C:4]1[CH:9]=[CH:8][C:7]([O:10][C:11]2[CH:16]=[CH:15][C:14]([CH2:17][CH:18]([NH:24][C:25]([O:27][C:28]([CH3:31])([CH3:30])[CH3:29])=[O:26])[C:19](=[O:23])[N:20]([CH3:22])[CH3:21])=[CH:13][CH:12]=2)=[N:6][CH:5]=1.[OH-].[Li+]>C1COCC1.O>[C:28]([O:27][C:25]([NH:24][CH:18]([C:19](=[O:23])[N:20]([CH3:21])[CH3:22])[CH2:17][C:14]1[CH:15]=[CH:16][C:11]([O:10][C:7]2[CH:8]=[CH:9][C:4]([C:3]([OH:32])=[O:2])=[CH:5][N:6]=2)=[CH:12][CH:13]=1)=[O:26])([CH3:30])([CH3:29])[CH3:31]Amide 18 (1.0 g, 2.25 mmol) was dissolved in THF (10 mL) and diluted with water (10 mL). Lithium hydroxide (0.107 g, 4.5 mmol) was added and the reaction mixture was stirred at room temperature for about 2 h. The THF was evaporated and the resulting aqueous layer was acidified with 2.0 M HCl and extracted into EtOAc (2×100 mL). The organic layer was washed with water (1×100 mL) and brine (1×100 mL), dried and concentrated to yield the desired acid compound 19 (1.0 g, 97%). 1H NMR (400 MHz, DMSO-d6): 13.1 (s, 1H), 8.64 (br, 1H), 8.27 (dd, J=8.4 and 2.0 Hz, 1H), 7.30 (d, J=8.4 Hz, 2H), 7.11 (d, J=8.8 Hz, 1H), 7.08 (m, 3H), 4.56 (m, 1H), 2.94 (s, 3H), 2.85-2.75 (m, 2H), 2.81 (s, 3H), 1.18 (s, 9H).
Wird geladen…