A mixture of 5-bromo-6-chloro-1H-indole (3.20 g, 13.9 mmol), sodium carbonate (3.68 g, 34.7 mmol), and 4-methoxyphenylboronic acid (2.41 g, 15.9 mmol) in EtOH (18 mL), toluene (18 mL) and water (18 mL) was degassed with N2 for 15 minutes, treated with tetrakis(triphenylphosphine)palladium(0) (1.20 g, 0.99 mmol) and heated to 90° C. for 23 hours. The cooled reaction mixture was poured into half-saturated NH4Cl solution (200 mL) and extracted with dichloromethane (3×120 mL). The combined organic layers were dried over Na2SO4 and concentrated in vacuo. The resulting dark solid was purified by flash chromatography (5-20% EtOAc/heptane) to give the title compound (1.40 g, 39%) as a white solid. MS (ES+) 258.5 (M+H)+. 1H NMR (500 MHz, CDCl3) δ 8.16 (br. s., 1 H), 7.56 (s, 1 H), 7.42 (d, J=8.1 Hz, 2 H), 7.24 (s, 1 H), 6.98 (d, J=8.1 Hz, 2 H), 6.55 (br. s., 1 H), 3.88 (s, 3 H).
