Trifluoromethanesulfonic acid → 6-Methoxy-2'-oxo-1',2'-dihydrospiro[1-benzofuran-3,3'-indole]-5-carbonitrile

To a stirred solution of 6-methoxy-1′-(4-methoxybenzyl)-2′-oxo-1′,2′-dihydrospiro[1-benzofuran-3,3′-indole]-5-carbonitrile (0.50 g, 1.2 mmol) in dichloromethane (5 mL) and trifluoroacetic acid (5 mL) was added trifluoromethanesulfonic acid (1.0 mL, 11 mmol). The reaction mixture was stirred at ambient temperature for 18 h and concentrated in vacuo. The residue was basified with saturated aqueous sodium bicarbonate and extracted with ethyl acetate. The organic phase was washed with water and brine, dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo. The residue was purified by column chromatography to afford 6-methoxy-2′-oxo-1′,2′-dihydrospiro[1-benzofuran-3,3′-indole]-5-carbonitrile (0.34 g, 96%): mp 185-186° C.; 1H NMR (300 MHz, CDCl3) δ 8.46 (s, 1H), 7.30-7.25 (m, 1H), 7.11-7.03 (m, 2H), 6.97-6.94 (m, 2H), 6.56 (s, 1H), 4.91 (ABq, 2H), 3.90 (s, 3H); MS (ES+) m/z 292.9 (M+1).

1. concentrationconcentrated in vacuo
2. extractionextracted with ethyl acetate
3. washThe organic phase was washed with water and brine
4. dry with materialdried over anhydrous sodium sulfate
5. filtrationfiltered
6. concentrationThe filtrate was concentrated in vacuo
7. customThe residue was purified by column chromatography

ORD record

ord-8293652983634f0fa6b1e9bce73a1573

Source dataset

uspto-grants-2013_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08415370B2