A heterogeneous mixture of 2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one (0.41 g, 1.4 mmol), cesium carbonate (1.1 g, 3.5 mmol), 2-(chloromethyl)-6-(trifluoromethyl)pyridine (0.33 g, 1.7 mmol) and N,N-dimethylformamide (10 mL) was stirred at ambient temperature for 16 h. The mixture was diluted with water (100 mL) and ethyl acetate (100 mL). The layers were separated and the aqueous layer was extracted with ethyl acetate (2×70 mL). The combined organic layers was washed with brine (100 mL), dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. The residue was purified by column chromatography and eluted with a 25% to 35% gradient of ethyl acetate in hexanes to afford 1′-{[6-(trifluoromethyl)pyridin-2-yl]methyl}-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one (0.44 g, 70%) as a colorless solid: mp 195-196° C.; 1H NMR (300 MHz, DMSO-d6) δ8.15-8.07 (m, 1H), 7.85-7.79 (m, 1H), 7.75-7.70 (m, 1H), 7.28-7.15 (m, 2H), 7.07-7.00 (m, 1H), 6.97-6.91 (m, 1H), 6.52 (s, 1H), 6.29 (s, 1H), 5.16 (ABq, J=42.6, 16.9 Hz, 2H), 4.75 (ABq, J=37.3, 9.3 Hz, 2H), 4.22-4.08 (m, 4H); 13C NMR (300 MHz, DMSO-d6) δ 176.8, 156.5, 154.6, 146.0 (q, JC-F=33.7 Hz), 144.1, 142.3, 139.4, 137.8, 131.7, 128.6, 125.4, 123.5, 123.0, 121.4 (q, JC-F=272.7 Hz), 121.1, 119.5 (m), 111.4, 109.1, 98.6, 79.5, 64.1, 63.5, 57.2, 44.2; MS (ES+) m/z 455.0 (M+1).
