[CH3:1][N:2]([CH2:11][CH2:12][N:13]1[CH2:18][CH2:17][S:16][C:15]2[CH:19]=[C:20]([N+:23]([O-])=O)[CH:21]=[CH:22][C:14]1=2)[CH2:3][C:4]([O:6][C:7]([CH3:10])([CH3:9])[CH3:8])=[O:5]>[Pd].CCO>[NH2:23][C:20]1[CH:21]=[CH:22][C:14]2[N:13]([CH2:12][CH2:11][N:2]([CH3:1])[CH2:3][C:4]([O:6][C:7]([CH3:8])([CH3:9])[CH3:10])=[O:5])[CH2:18][CH2:17][S:16][C:15]=2[CH:19]=1A round bottom flask containing tert-butyl 2-(methyl(2-(7-nitro-2H-benzo[b][1,4]thiazin-4(3H)-yl)ethyl)amino)acetate (925 mg, 2.52 mmol) was purged with argon and then charged with palladium on carbon (10% wt; 268 mg, 0.252 mmol). To this mixture was added EtOH (40 mL). The resulting suspension was evacuated using a pump, and hydrogen was let into the system via a balloon. The mixture was stirred under a balloon filled with hydrogen for 3 hours. The balloon was removed, and argon was bubbled through the suspension for 10 minutes. The mixture was filtered through a pad of Celite, and the Celite pad was rinsed with methanol (20 mL). The filtrate was concentrated, and the residue was dried under reduced pressure to give the title compound (850 mg, quantitative). 1H-NMR (CDCl3) δ 6.59 (d, J=8.7 Hz, 1H), 6.45 (d, J=2.4 Hz, 1H), 6.40 (dd, J=2.7, 8.4 Hz, 1H), 3.54-3.45 (m, 2H), 3.33 (t, J=7.2 Hz, 2H), 3.27 (brs, 2H), 3.20 (s, 2H), 3.04-2.98 (m, 2H), 2.71 (t, J=7.5 Hz, 2H), 2.42 (s, 3H), 1.46 (s, 9H); ESI-MS (m/z, %): 338 (MH+, 95), 282 (100).
Wird geladen…