To a solution of 2-(6-bromo-1,8-diethyl-1,3,4,9-tetrahydro-pyrano[3,4-b]indol-1-yl)-ethanol (3.8 g, 10.8 mmol) in ethylene glycol dimethyl ether (50 mL) was added potassium phosphate (6.37 g, 30 mmol), phenylboronic acid (1.83 g, 15 mmol), and [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium (II) complex with dichloromethane. The reaction mixture was heated at 90° C. (oil bath) overnight. It was quenched with water and extracted with ethyl acetate. Extracts were dried over magnesium sulfate and concentrated under reduced pressure. The crude product was purified by column chromatography (silica gel, 50% ethyl acetate/hexane, followed by Sephadex LH-20, 50% chloroform/hexane) to give the title compound (0.75 g, 20% yield). 1H NMR (CDCl3) δ 7.77 (s, 1H), 7.66 (d, 1H), 7.63 (m, 1H), 7.56 (d, 1H), 7.44 (m, 3H), 7.32 (m, 1H), 4.06 (m, 2H), 3.72 (m, 3H), 2.91 (m, 3H), 2.81 (dt, 1H), 2.65 (dd, 1H), 2.20 (m, 1H), 2.07 (m, 2H), 1.40 (t, 3H), 0.95 (t, 3H). ES-MS (m/z) 348 [M−1]−.
