2'-Hydroxyacetophenone → 1-[2-(Difluoromethoxy)phenyl]ethan-1-one

Temperature

-20 °C

Potassium hydroxide (105 g, 1872 mmol) was suspended in a mixture of acetonitrile (200 mL) and water (200 mL) and cooled to approximately −20° C. 1-(2-Hydroxyphenyl)ethanone (11.28 mL, 93.7 mmol) was added dropwise, followed by diethyl[bromo(difluoro)methyl]phosphonate (33.27 mL, 187.3 mmol) over 15 minutes. The mixture was then allowed to warm to room temperature over 1 h. The mixture was extracted with ethyl acetate (3×200 mL), then the combined organic layers were washed with brine (50 mL), dried over magnesium sulfate and concentrated under vacuum. The mixture was purified by flash chromatography to afford the title compound (16.0 g, 92%) as a colourless oil. Method B HPLC-MS: MH+ m/z 187, RT 1.77 minutes.

1. temperatureto warm to room temperature over 1 h
2. extractionThe mixture was extracted with ethyl acetate (3×200 mL)
3. washthe combined organic layers were washed with brine (50 mL)
4. dry with materialdried over magnesium sulfate
5. concentrationconcentrated under vacuum
6. customThe mixture was purified by flash chromatography

ORD record

ord-bc33d63f1a9a4a7bbf7f74bf98d64549

Source dataset

uspto-grants-2016_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09309243B2