Reaction Steps
A slurry of methyl 2-bromo-3-cyclohexyl-1H-indole-6-carboxylate (1.75 g, 5.22 mmol), LiCl (880 mg, 21.0 mmol), 1M aqueous Na2CO3 (13 mL, 13.0 mmol), Pd(PPh3)4 (600 mg, 0.52 mmol) and tert-butyl 2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenylcarbamate (2.5 g, 7.8 mmol) in toluene (19 mL) and EtOH (19 mL) was heated at relfux for 2 h. The reaction mixture was cooled and concentrated to dryness under vacuum. The residue was treated with H2O (120 mL) and extracted with EtOAc(2×200 mL). The combined organics were washed with brine (2×20 mL), dried (MgSO4), filtered, concentrated and purified by SiO2 chromatography (5–25% EtOAc/hexanes) to yield methyl 2-(2-(tert-butoxycarbonyl)phenyl)-3-cyclohexyl-1H-indole-6-carboxylate (1.8 g, 4.0 mmol, 77%) as a yellow-pink solid. 1HNMR (500 MHz, CDCl3) δ. 8.26 (d, J=8.5 Hz, 1H), 8.14 (s, 1H), 8.11 (s, 1 H), 7.86 (d, J=8.2 Hz, 1H), 7.82 (dd, J=8.2, 1.5 Hz, 1H), 7.43 (ddd, J=8.5, 7.3, 1.5 Hz, 1H), 7.28 (d, J=7.6, 1.5 Hz, 1H), 7.11 (ddd, J=7.6, 7.3, 1.2 Hz, 1H), 6.67 (br s, 1H), 3.94 (s, 3H), 2.56 (tt, J=12.1, 3.5 Hz, 1H), 1.97–1.22 (m, 10H), 1.45 (s, 9H). LCMS: m/e 449 (M+H)+, ret time 2.39 min, column C, 2 minute gradient, start at 0% B.
