Cesium carbonate → 6-Fluoro-1'-(4-methoxybenzyl)-2'-oxo-1',2'-dihydrospiro[1-benzofuran-3,3'-indole]-5-carbonitrile

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Reaction Steps

To a stirred solution of 2-fluoro-4-hydroxy-5-[1-(4-methoxybenzyl)-2-oxo-2,3-dihydro-1H-indol-3-yl]benzonitrile (10.50 g, 27.03 mmol) and chloroiodomethane (5.00 mL, 68.7 mmol) in tetrahydrofuran (200 mL) and N,N-dimethylformamide (50 mL) was added cesium carbonate (26.40 g, 81.02 mmol) under nitrogen. The reaction mixture was stirred at ambient temperature for 20 h and filtered through a pad of diatomaceous earth. The filtrate was concentrated in vacuo. The residue was subjected to column chromatography and eluted with ethyl acetate/hexanes (1/3) to afford 6-fluoro-1′-(4-methoxybenzyl)-2′-oxo-1′,2′-dihydrospiro[1-benzofuran-3,3′-indole]-5-carbonitrile (5.27 g, 48%): mp 142-143° C.; 1H NMR (300 MHz, CDCl3) δ 7.29-7.23 (m, 3H), 7.11-7.02 (m, 2H), 6.89-6.85 (m, 4H), 6.77 (d, J=9.0 Hz, 1H), 5.12-4.75 (m, 4H), 3.78 (s, 3H); MS (ES+) m/z 400.7 (M+1).

Provenance & Evidence