Hydrochloric Acid → 6-Hydroxy-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 2,4-dihydroxy-5-[1-(4-methoxybenzyl)-2-oxo-2,3-dihydro-1H-indol-3-yl]benzonitrile (9.40 g, 24.3 mmol) and chloroiodomethane (4.40 mL, 60.4 mmol) in tetrahydrofuran (250 mL) was added cesium carbonate (23.8 g, 73.0 mmol) under nitrogen. The reaction mixture was stirred at ambient temperature for 20 h and 5% w/v hydrochloric acid was added. The mixture was extracted with ethyl acetate (3×200 mL). The combined organic extracts were washed with water and brine, and dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo. The residue was subjected to column chromatography and eluted with ethyl acetate to afford 6-hydroxy-1′-(4-methoxybenzyl)-2′-oxo-1′,2′-dihydrospiro[1-benzofuran-3,3′-indole]-5-carbonitrile (2.57 g, 26%): mp 112-114° C. (ethyl acetate/hexanes); 1H NMR (300 MHz, DMSO-d6) δ 11.32 (s, 1H), 7.29-7.16 (m, 4H), 7.02-6.97 (m, 2H), 6.89-6.85 (m, 3H), 6.54 (s, 1H), 4.93-4.77 (m, 4H), 3.68 (s, 3H); MS (ES+) m/z 398.8 (M+1).

Provenance & Evidence