Tetrabutylammonium Fluoride → 4-{[6-(4-Fluorophenyl)-2-naphthyl]sulfonyl}-1H-benzimidazole

Participants

Reaction Steps

To a stirring solution of 4-{[6-(4-fluorophenyl)-2-naphthyl]sulfonyl}-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-benzimidazole (260 mg, 0.49 mmol) in THF (5 mL) was added tetrabutylammonium fluoride (0.60 mL of 1 M solution in THF; 0.6 mmol), and the resulting mixture was heated at reflux for 5 hours. The mixture was allowed to cool to room temperature, then was diluted with water (100 mL) and washed with ethyl acetate (2×50 mL), The combined organic layers were washed with water, then with saturated sodium chloride solution, were dried (MgSO4) and concentrated in vacuo. The crude product was purified by flash chromatography on silica gel, eluting first with 1:1 ethyl acetate:isohexane, then with 100% ethyl acetate. The resulting material was purified further by flash chromatography on silica gel, eluting with 50% to 70% ethyl acetate in isohexane, and the resulting material was triturated using a 1:1 mixture of diethyl ether and isohexane, to afford the product as a white amorphous solid (85 mg, 43%). 1H NMR (500 MHz, d6-DMSO): δ 12.96 (1H, s), 8.89 (1H, s), 8.38 (1H, s), 8.30 (1H, s), 8.26 (1H, d, J=8.6 Hz), 8.14-8.08 (2H, m), 8.00 (1H, d, J=8.6 Hz), 7.95 (2H, t, J=6.8 Hz), 7.88 (2H, dd, J=5.4, 8.7 Hz), 7.45 (1H, t, J=7.9 Hz), 7.36 (2H, t, J=8.8 Hz); m/z (ES+) 403 [MH+].

Provenance & Evidence