Trifluoroacetic acid → 1-(2-cyclopropylethyl)-3-(6-hydroxy-1,3-benzodioxol-5-yl)-1,3-dihydro-2H-indol-2-one

To a solution of 1-(2-cyclopropylethyl)-3-hydroxy-3-(6-hydroxy-1,3-benzodioxol-5-yl)-1,3-dihydro-2H-indol-2-one (2.22 g, 6.27 mmol) in dichloromethane (30.0 mL) was added trifluoroacetic acid (2.12 g, 18.8 mmol) and triethylsilane (2.14 g, 18.8 mmol). The brown solution was stirred at ambient temperature for 0.5 h and concentrated in vacuo to dryness. The residue was diluted with dichloromethane (100 mL), washed with water (3×50.0 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo to dryness. The residue was subjected to column chromatography eluting with ethyl acetate/hexane (20/80) to give the title compound (1.69 g, 80%) as a brown solid: 1H NMR (300 MHz, CDCl3) δ 9.21-9.10 (br, 1H), 7.38-7.30 (m, 2H), 7.16 (t, 1H), 6.96 (d, 1H), 6.63 (s, 1H), 6.33 (s, 1H), 5.84 (dd, 2H), 5.01 (s, 1H), 3.87-3.72 (m, 2H), 1.66-1.46 (m, 2H), 0.69-0.59 (m, 1H), 0.43-0.30 (m, 2H), 0.09-0.06 (m, 2H); 13C NMR (75 MHz, CDCl3) δ 178.8, 151.3, 147.6, 144.1, 141.5, 128.7, 126.2, 123.1, 115.2, 109.5, 109.4, 106.5, 101.5, 101.2, 47.4, 40.5, 32.2, 8.6, 4.3, 4.2; MS (ES+) m/z 338.3 (M+1).

1. concentrationconcentrated in vacuo to dryness
2. additionThe residue was diluted with dichloromethane (100 mL)
3. washwashed with water (3×50.0 mL)
4. dry with materialdried over anhydrous sodium sulfate
5. filtrationfiltered
6. concentrationThe filtrate was concentrated in vacuo to dryness
7. washeluting with ethyl acetate/hexane (20/80)

ORD record

ord-670895a430924a7d861326217ffe856f

Source dataset

uspto-grants-2011_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07935721B2