[C:1]([O:5][CH2:6][CH2:7][C:8]1[CH:13]=[CH:12][C:11]([N:14]2[C:18]3=[N:19][CH:20]=[C:21]([NH2:24])[C:22]([CH3:23])=[C:17]3[N:16]=[C:15]2[CH2:25][CH3:26])=[CH:10][CH:9]=1)(=[O:4])[CH2:2][CH3:3].N1C=CC=CC=1.[CH3:33][S:34](Cl)(=[O:36])=[O:35]>ClCCl>[C:1]([O:5][CH2:6][CH2:7][C:8]1[CH:13]=[CH:12][C:11]([N:14]2[C:18]3=[N:19][CH:20]=[C:21]([NH:24][S:34]([CH3:33])(=[O:36])=[O:35])[C:22]([CH3:23])=[C:17]3[N:16]=[C:15]2[CH2:25][CH3:26])=[CH:10][CH:9]=1)(=[O:4])[CH2:2][CH3:3]To a stirred solution of 2-[4-(6-amino-2-ethyl-7-methyl-3H-imidazo[4,5-b]pyridin-3-yl)phenyl]ethyl propionate (step 4, 1.0 g, 3.0 mmol) and pyridine (280 mg, 3.5 mmol) in dichloromethane (18 mL) was added methanesulfonyl chloride (372 mg, 3.3 mmol) at 0° C., and the mixture was stirred at room temperature for 16 h. The reaction was quenched with water (10 mL), and the mixture was extracted with dichloromethane (50 mL). The organic layer was washed with brine (50 mL), dried (MgSO4), and concentrated. Purification by flash column chromatography on silica gel eluting with ethyl acetate (gradient elution from 1:1 to 1:2) afforded 890 mg (70%) of the title compound as an amber oil: 1H-NMR (CDCl3) δ 8.26 (1H, s), 7.43 (2H, d, J=8.4 Hz), 7.32 (2H, d, J=8.2 Hz), 7.00 (1H, br.s), 4.35 (2H, t, J=7.0 Hz), 3.03-3.01 (5H, m), 2.85 (2H, q, J=7.5 Hz), 2.75 (3H, s), 2.35 (2H, q, J=7.5 Hz), 1.30 (3H, t, J=7.5 Hz), 1.14 (3H, t, J=7.5 Hz).
Loading…