A 50-mL three-neck round-bottomed flask equipped with a reflux condenser, magnetic stirrer and nitrogen inlet was charged with 104a (236 mg, 1.00 mmol), 102f (536 mg, 1.20 mmol), sodium carbonate (318 mg, 3.00 mmol), DMF (5 mL), water (2.5 mL) and 1,4-dioxane (8 mL). After bubbling nitrogen through the resulting suspension for 30 min, tetrakis(triphenylphosphine)palladium(0) (116 mg, 0.100 mmol) was added, and the reaction mixture was heated at reflux for 14 h. After this time, the mixture was cooled to room temperature and diluted with ethyl acetate (150 mL) and water (30 mL). The organic layer was separated, and the aqueous layer was extracted with ethyl acetate (3×50 mL). The combined organic layers were dried over sodium sulfate and concentrated under reduced pressure. The residue was dissolved in a mixture of THF (8 mL), methanol (4 mL) and water (4 mL). To the resulting solution was added lithium hydroxide monohydrate (420 mg, 10.0 mmol). The mixture was stirred for 4 h at room temperature and then concentrated in vacuo. The residue was partitioned between ethyl acetate (150 mL) and water (30 mL). The organic layer was separated, and the aqueous layer was extracted with ethyl acetate (3×50 mL). The combined organic layers were dried over sodium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography (silica, 0% to 10% methanol/methylene chloride) to afford a 38% yield (187 mg) of 104 as an off-white solid: mp 236-237° C.; 1H NMR (500 MHz, DMSO-d6) δ 9.40 (s, 1H), 8.58 (s, 1H), 8.28 (dd, 1H, J=5.0, 1.6 Hz), 7.71 (m, 3H), 7.61 (dd, 1H, J=7.9, 1.5 Hz), 7.50 (m, 4H), 6.96 (m, 1H), 4.93 (s, 2H), 4.68 (t, 1H, J=4.9 Hz), 4.42 (d, 2H, J=5.0 Hz), 3.79 (s, 3H), 1.36 (s, 9H); MS (ESI+) m/z 496.2 (M+H).
