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

Temperature

0 °C

To a solution of 4-bromo-3-(6-hydroxy-1,3-benzodioxol-5-yl)-1-pentyl-1,3-dihydro-2H-indol-2-one (7.50 g, 17.9 mmol) in dry dichloromethane (150 mL) was added triethylamine (10.9 g, 108 mmol) and chlorotrimethylsilane (7.80 g, 71.8 mmol) at 0° C. The reaction mixture was stirred at 0° C. for 2 h and diluted with dichloromethane (100 mL). The mixture was washed with water (3×50.0 mL), dried over anhydrous magnesium sulfate and filtered. The filtrate was concentrated in vacuo to dryness. The residue was dissolved in THF (150 mL) followed by the additions of formaldehyde solution (4.90 mL, 179 mmol, 37 wt % in water) and ytterbium (III) trifluoromethanesulfonate (1.11 g, 1.79 mmol). The resulting mixture was stirred at ambient temperature for 36 h. After the solvent was removed under reduced pressure, the residue was diluted with dichloromethane (200 mL), washed with saturated sodium bicarbonate (50.0 mL), saturated ammonium chloride (50.0 mL) and water (100 mL). The organic layer was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo to dryness to yield the title compound (6.32 g, 79%) as a fluffy solid: 1H NMR (300 MHz, CDCl3) δ 8.28 (s, 1H), 7.10 (t, 1H), 7.00 (dd, 1H), 6.89 (dd, 1H), 6.83 (s, 1H), 6.27 (s, 1H), 6.85 (dd, 2H), 4.52-4.41 (m, 2H), 3.90 (dd, 1H), 3.70-3.65 (m, 2H), 1.68-1.57 (m, 2H), 1.36-1.29 (m, 4H), 0.83 (t, 3H); 13C NMR (75 MHz, CDCl3) δ 178.1, 150.3, 147.2, 147.2, 140.5, 129.6, 129.2, 125.6, 118.4, 114.8, 109.2, 106.9, 101.0, 98.2, 62.6, 57.6, 39.9, 28.9, 26.7, 22.2, 13.5.

1. washThe mixture was washed with water (3×50.0 mL)
2. dry with materialdried over anhydrous magnesium sulfate
3. filtrationfiltered
4. concentrationThe filtrate was concentrated in vacuo to dryness
5. dissolutionThe residue was dissolved in THF (150 mL)
6. stirringThe resulting mixture was stirred at ambient temperature for 36 h
7. customAfter the solvent was removed under reduced pressure
8. additionthe residue was diluted with dichloromethane (200 mL)
9. washwashed with saturated sodium bicarbonate (50.0 mL), saturated ammonium chloride (50.0 mL) and water (100 mL)
10. dry with materialThe organic layer was dried over anhydrous sodium sulfate
11. filtrationfiltered
12. concentrationThe filtrate was concentrated in vacuo to dryness

ORD record

ord-e193b620146a4d7a89af0d9f5179e01b

Source dataset

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08106087B2