Reaction Steps
To a solution of tert-butyl 8,9-dichloro-1,4,5,6-tetrahydroazepino[4,5-b]indole-3(2H)-carboxylate (0.40 g, 1.1 mmol) in DMF (5 mL), sodium hydride (60% dispersion in mineral oil, 68 mg, 1.7 mmol) was added. After 20 min, β-bromophenetole (0.31 mL, 2.3 mmol) was added. The reaction was quenched with saturated aqueous NH4Cl after 2 h and extracted with EtOAc (3×15 mL). The combined organic extracts were washed with brine, dried over Na2SO4, decanted, and concentrated. The crude product was purified by two column chromatographies (Biotage, 40S) with heptane/EtOAc (17:3) and (Biotage, 40M) with heptane/EtOAc (9:1) to give 0.41 g (76%) of a white solid: mp 135.5-137.5° C.; 1H NMR (300 MHz, CDCl3) δ 7.50 (d, J=4.5 Hz, 1H), 7.41 (d, J=7.5 Hz, 1H), 6.93 (m, 1H), 6.77 (d, J=7.9 Hz, 2H), 4.42 (m, 2H), 4.17 (t, J=5.3 Hz, 2H), 3.70 (m, 4H), 3.09 (m, 2H), 2.89 (m, 2H), 1.49 (s, 9H); IR (diffuse reflectance) 1678, 1494, 1469, 1406, 1364, 1297, 1245, 1233, 1172, 1119, 1106, 941, 875, 758, 691 cm−1; MS (ES+) m/z 475 (M+H+), 498, 497, 348, 346, 255, 252, 169, 137, 121, 90; Anal. Calcd for C25H28Cl2N2O3: C, 63.16; H, 5.94; N, 5.89; found: C, 63.22; H, 6.00; N, 5.88.
