Trifluoroacetic acid → 2-fluoro-4-hydroxy-5-[1-(4-methoxybenzyl)-2-oxo-2,3-dihydro-1H-indol-3-yl]benzonitrile

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Reaction Steps

To a stirred suspension of 2-fluoro-4-hydroxy-5-[3-hydroxy-1-(4-methoxybenzyl)-2-oxo-2,3-dihydro-1H-indol-3-yl]benzonitrile (12.0 g, 29.7 mmol) in triethylsilane (14.2 mL, 88.9 mmol) was added trifluoroacetic acid (10.0 mL, 129 mmol). The reaction mixture was stirred at ambient temperature for 168 h and concentrated in vacuo. The residue was recrystallized from ethyl acetate/hexanes to afford 2-fluoro-4-hydroxy-5-[1-(4-methoxybenzyl)-2-oxo-2,3-dihydro-1H-indol-3-yl]benzonitrile (10.5 g, 90%): 1H NMR (300 MHz, CDCl3) δ 7.37-7.12 (m, 7H), 6.94 (d, J=6.0 Hz, 1H), 6.85-6.79 (m, 3H), 5.07 (s, 1H), 4.88 (ABq, 2H), 3.75 (s, 3H); MS (ES+) m/z 388.9 (M+1).

Provenance & Evidence