[C:1]([O:5][C:6]([NH:8][C:9]1[CH:10]=[C:11]([N:19]2[CH2:24][CH2:23][N:22]([C:25]([O:27][C:28]([CH3:31])([CH3:30])[CH3:29])=[O:26])[CH2:21][CH2:20]2)[CH:12]=[CH:13][C:14]=1[C:15]([O:17][CH3:18])=[O:16])=[O:7])([CH3:4])([CH3:3])[CH3:2].C(O)(C(F)(F)F)=O.C1C(=O)N([Cl:46])C(=O)C1.CO>C(Cl)Cl>[C:1]([O:5][C:6]([NH:8][C:9]1[C:14]([C:15]([O:17][CH3:18])=[O:16])=[CH:13][C:12]([Cl:46])=[C:11]([N:19]2[CH2:20][CH2:21][N:22]([C:25]([O:27][C:28]([CH3:31])([CH3:30])[CH3:29])=[O:26])[CH2:23][CH2:24]2)[CH:10]=1)=[O:7])([CH3:3])([CH3:4])[CH3:2]To a solution of tert-butyl 4-(3-(tert-butoxycarbonylamino)-4-(methoxycarbonyl)phenyl)piperazine-1-carboxylate (360 mg, 0.827 mmol) in DCM (4 mL) at −78° C. was added TFA (0.064 mL, 0.827 mmol). The reaction mixture was warmed to 0° C., followed by the addition of NCS (110 mg, 0.827 mmol) and MeOH (2.000 mL). The resulted reaction mixture was stirred at RT for 16 hours. The product was purified by flash chromatography (2% EtOAc/DCM, Rf 0.50) to give 150 mg (77% yield) of tert-Butyl 4-(5-(tert-butoxycarbonylamino)-2-chloro-4-(methoxycarbonyl)phenyl)piperazine-1-carboxylate. 1H-NMR (CDCl3, 400 MHz): δ 10.31 (1H, s), 8.18 (1H, s), 7.98 (1H, s), 3.90 (3H, s), 3.61 (4H, t, J=4.8 Hz), 3.14 (4H, t, J=4.8 Hz), 1.53 (9H, s), 1.49 (9H, s).
Wird geladen…