反应详情

To a solution of 6-hydroxyspiro[1-benzofuran-3,3′-indol]-2′(1′H)-one (3.0 g, 11.8 mmol) in anhydrous N,N-dimethylformamide (30 mL) under nitrogen were added imidazole (1.97 g, 28.9 mmol) and triisopropylsilyl chloride (6.03 mL, 28.5 mmol). The reaction mixture was stirred at ambient temperature for 16 h. The reaction mixture was concentrated in vacuo to dryness. The residue was extracted with ethyl acetate (2×50 mL), the combined organic solution was dried over sodium sulfate, and filtered. The filtrate was concentrated and purified by flash chromatography with 30% ethyl acetate in hexanes to afford 6-{[tris(1-methylethyl)silyl]oxy}spiro[1-benzofuran-3,3′-indol]-2′(1′H)-one (2.68 g, 69% yield) as colorless solid: 1H NMR (300 MHz, CDCl3) δ 8.48-8.08 (br, 1H), 7.29-6.90 (m, 4H), 6.10 (d, J=8.1 Hz, 1H), 6.50 (d, J=2.1 Hz, 1H), 6.35 (dd, J=8.1, 2.1 Hz, 1H), 4.96 (d, J=9.0 Hz, 1H), 4.69 (d, J=9.0 Hz, 1H), 1.34-0.98 (m, 21H).

1. concentrationThe reaction mixture was concentrated in vacuo to dryness
2. extractionThe residue was extracted with ethyl acetate (2×50 mL)
3. dry with materialthe combined organic solution was dried over sodium sulfate
4. filtrationfiltered
5. concentrationThe filtrate was concentrated
6. custompurified by flash chromatography with 30% ethyl acetate in hexanes