Trifluoroacetic acid → 4-bromo-3-(6-hydroxy-1,3-benzodioxol-5-yl)-1-pentyl-1,3-dihydro-2H-indol-2-one

To a solution of 4-bromo-3-hydroxy-3-(6-hydroxy-1,3-benzodioxol-5-yl)-1-pentyl-1,3-dihydro-2H-indol-2-one (34.9 g, 80.4 mmol) in dichloromethane (100 mL) was added trifluoroacetic acid (18.7 g, 161 mmol) and triethylsilane (18.3 g, 161 mmol). The brown solution was stirred at ambient temperature for 3 h and concentrated in vacuo to dryness. The residue was diluted with dichloromethane (200 mL), washed with saturated ammonium chloride solution (50.0 mL), brine (3×50.0 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo to dryness. The residue was crystallized from ether to give the title compound (16.5 g, 49%) as a brown solid: 1H NMR (300 MHz, CDCl3) δ 7.29-7.21 (m, 2H), 7.14 (dd, 1H), 6.58 (s, 1H), 6.10 (s, 1H), 5.85 (dd, 2H), 5.01 (s, 1H), 3.75-3.55 (m, 2H), 1.69-1.56 (m, 2H), 1.35-1.21 (m, 4H), 0.86 (t, 3H); 13C NMR (75 MHz, CDCl3) δ 177.9, 150.9, 147.6, 145.4, 141.6, 130.3 127.1 126.8, 120.8, 113.3 108.0, 106.7, 101.5, 101.2, 59.9, 48.6, 40.7, 28.9, 26.9, 22.3 13.9; MS (ES+) m/z 418.3 (M+1), 420.3 (M+1).

1. concentrationconcentrated in vacuo to dryness
2. additionThe residue was diluted with dichloromethane (200 mL)
3. washwashed with saturated ammonium chloride solution (50.0 mL), brine (3×50.0 mL)
4. dry with materialdried over anhydrous sodium sulfate
5. filtrationfiltered
6. concentrationThe filtrate was concentrated in vacuo to dryness
7. customThe residue was crystallized from ether

ORD record

ord-246e8e7be96c41888212393761d270c4

Source dataset

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08106087B2