Reaction Steps
To a solution of 5-bromo-3-(7-hydroxy-2,3-dihydro-1,4-benzodioxin-6-yl)-1-(pyridin-2-ylmethyl)-1,3-dihydro-2H-indol-2-one (2.00 g, 4.40 mmol) in anhydrous N,N-dimethylformamide (25 mL) was added cesium carbonate (4.30 g, 13.2 mmol) and chloroiodomethane (0.85 g, 4.9 mmol). The solution was stirred at ambient temperature for 16 h and poured into water (100 mL). The mixture was extracted with ethyl acetate (3×50 mL) and the combined ethyl acetate extracts were washed with brine (2×35 mL), dried over magnesium sulfate, filtered and concentrated in vacuo. The residue was triturated in dichloromethane/diethyl ether (2/5, 14 mL) to afford 5′-bromo-1′-(pyridin-2-ylmethyl)-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one (1.44 g, 72%) as a beige solid: mp>250° C. (dichloromethane/diethyl ether); 1H NMR (300 MHz, CDCl3) 8.57-8.52 (m, 1H), 7.69-7.61 (m, 1H), 7.33-7.27 (m, 3H), 7.26-7.16 (m, 1H), 6.77 (d, J=8.3 Hz, 1H), 6.49 (s, 1H), 6.30 (s, 1H), 5.16 (d, J=15.8 Hz, 1H), 4.97-4.87 (m, 2H), 4.64 (d, J=9.0 Hz, 1H), 4.22-4.08 (m, 4H); 13C NMR (75 MHz, CDCl3) δ 176.9, 155.2, 155.1, 149.6, 144.9, 141.1, 138.4, 137.2, 134.2, 131.7, 127.0, 122.9, 121.7, 120.4, 116.1, 111.7, 111.1, 99.5, 80.0, 64.5, 63.9, 58.2, 46.1; MS (ES+) m/z 465.0 (M+1), 467.0 (M+1).
