Reaction Steps
A mixture of 3′-[(3-bromopyridin-2-yl)methyl]-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,1′-inden]-2′(3′H)-one (0.233 g, 0.50 mmol), sodium methanesulfonate (0.071 g, 0.60 mmol), copper iodide (0.010 g, 0.05 mmol), and the sodium salt of L-proline (0.014 g, 0.10 mmol) were combined in dimethyl sulfoxide (1 mL) and heated at 95° C. for 48 h, then stirred at ambient temperature for 30 h. The reaction mixture was diluted with ethyl acetate (50 mL) and washed with water (100 mL), dried over sodium sulfate, filtered and concentrated in vacuo. The residue was triturated from methanol and further purified by column chromatography, and eluted with a 0% to 50% gradient of ethyl acetate in dichloromethane to yield 3′-{[3-(methylsulfonyl)pyridin-2-yl]methyl}-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,1′-inden]-2′(3′H)-one (0.103 g, 44%) as a colorless solid: mp>250° C.; 1H NMR (300 MHz, DMSO-d6) δ 8.69 (d, J=4.2 Hz, 1H), 8.35 (dd, J=8.0, 0.5 Hz, 1H), 7.64 (dd, J=7.9, 4.7 Hz, 1H), 7.24 (dd, J=7.7, 7.7 Hz, 1H), 7.18 (d, J=7.3 Hz, 1H), 7.05-6.99 (m, 2H), 6.50 (s, 1H), 6.39 (s, 1H), 5.50 (ABq, 2H), 4.76 (ABq, 2H), 4.19-4.12 (m, 4H), 3.52 (s, 3H); 13C NMR (75 MHz, DMSO-d6) δ 177.6, 155.0, 153.7, 153.6, 144.6, 143.4, 138.4, 138.2, 135.9, 132.4, 129.1, 124.1, 123.9, 123.3, 122.1, 112.2, 109.8, 99.1, 79.6, 64.7, 64.1, 57.7, 44.2, 42.7; MS (ES+) m/z 465.0 (M+1).
