Hydrogen Bromide → 1,1,1-Trifluoro-4-(4-hydroxyphenyl)butan-2-one

Temperature

120 °C

A 100 mL round bottom flask, fitted with reflux condenser, magnetic stirrer and argon inlet was charged with 2.05 g (6.7 mmol) of ethyl 2-(4-methoxybenzyl)-3-oxo-4,4,4-trifluorobutanoate (I), 20 mL of 31% (w/v) hydrogen bromide in acetic acid, and 10 mL of water. This mixture was heated overnight at 120° C., cooled, concentrated under reduced pressure and partitioned between dichloromethane and water. The organic layer was extracted sequentially with aqueous bisulfite, and saturated sodium bicarbonate, and then dried over anhydrous magnesium sulfate. Solvent was removed under reduced pressure. The crude reaction mixture was chromatographed on a 50 mm×300 mm silica gel column with ethyl acetate/hexane (50/50). Similar fractions were combined and the solvent was removed under reduced pressure to yield 600 mg (41%) as a clear oil. NMR(CDC13): 2.95(m,4H), 5.40(bs, 1H), 6.93(dd,4H) J=4, 60 Hz.

1. customA 100 mL round bottom flask, fitted
2. temperaturewith reflux condenser, magnetic stirrer and argon inlet
3. temperaturecooled
4. concentrationconcentrated under reduced pressure
5. custompartitioned between dichloromethane and water
6. extractionThe organic layer was extracted sequentially with aqueous bisulfite, and saturated sodium bicarbonate
7. dry with materialdried over anhydrous magnesium sulfate
8. customSolvent was removed under reduced pressure
9. customThe crude reaction mixture
10. customwas chromatographed on a 50 mm×300 mm silica gel column with ethyl acetate/hexane (50/50)
11. customthe solvent was removed under reduced pressure
12. customto yield 600 mg (41%) as a clear oil

ORD record

ord-c18c20fe54f84653933d34292f9d7c77

Source dataset

uspto-grants-1993_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05208143