Ethyl bromoacetate → (4-Cyano-3-fluorophenoxy)acetic acid

The mixture of 2-fluoro-4-hydroxybenzonitrile (274 mg, 2.1 mmol), potassium carbonate (910 mg, 6.6 mmol), ethyl bromoacetate (500 mg, 3.0 mmol) and acetone (25 ml) was refluxed for 6 h. After cooling, the mixture was filtered to remove potassium carbonate. The filtrate was concentrated under reduced pressure. To this residue, 10 ml of dioxane and 14 ml 5% sodium hydroxide solution were added. After the mixture was stirred at room temperature overnight, it was acidified with concentrated hydrochloric acid to pH 1, and then extracted three times with ethyl acetate (20 ml each). Organic phases were combined, washed with water and brine, dried over magnesium sulfate, filtered, and then evaporated in vacuo. The residue was recrystallized from ethanol and petroleum ether to give 268 mg 4-cyano-3-fluorophenoxyacetic acid as white crystals, mp 150-152° C.

1. temperaturewas refluxed for 6 h
2. temperatureAfter cooling
3. filtrationthe mixture was filtered
4. customto remove potassium carbonate
5. concentrationThe filtrate was concentrated under reduced pressure
6. additionTo this residue, 10 ml of dioxane and 14 ml 5% sodium hydroxide solution were added
7. extractionextracted three times with ethyl acetate (20 ml each)
8. washwashed with water and brine
9. dry with materialdried over magnesium sulfate
10. filtrationfiltered
11. customevaporated in vacuo
12. customThe residue was recrystallized from ethanol and petroleum ether

ORD record

ord-e0158d5e4e2b4d1698cb0564a8591b4f

Source dataset

uspto-grants-2002_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06350756B1