[CH2:1]([NH:8][CH2:9][CH2:10][NH:11][C:12](=[O:18])[O:13][C:14]([CH3:17])([CH3:16])[CH3:15])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.I[CH3:20]>C(Cl)(Cl)Cl>[CH2:1]([N:8]([CH2:9][CH2:10][NH:11][C:12](=[O:18])[O:13][C:14]([CH3:15])([CH3:17])[CH3:16])[CH3:20])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1To a cooled (˜5° C.) solution of compound A (6.2 g, 25.0 mmol) and TEA (3.0 g, 29.7 mmol, 4.13 mL) in chloroform (50 mL) was added iodomethane (4.2 g, 29.7 mmol, 1.85 mL). The pressure tube was sealed, and the mixture stirred at ambient temperature for 20 h. The mixture was then precipitated with ether (300 mL); the white solid was filtered off and washed with ether (50 mL). The filtrate was concentrated and the residual yellow oil (5.2 g) was purified by silica gel column chromatography (2-10% MeOH gradient in DCM) to give compound B (3.3 g, 12.5 mmol, 50%) as a colorless oil. TLC Rf (DCM/MeOH 9:1): 0.55. LC-MS [M+H] 264.3 (C15H24N2O2+H, calc: 264.4).
Wird geladen…