4-Nitro-3-trifluoromethylphenol → [4-Nitro-3-(trifluoromethyl)phenoxy]acetic acid

The mixture of 4-nitro-3-trifluoromethylphenol (414 mg, 2.0 mmol), potassium carbonate (910 mg, 6.6 mmol), ethyl bromoacetate (500 mg, 3.0 mmol) and acetone (25 ml) was refluxed for 8 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 2, 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 separated by column chromatography (eluent: ethyl acetate: EtOH 9:1) to give 35 mg 4-nitro-3-trifluoromethylphenoxyacetic acid as white solid, mp 92-95° C.

1. temperaturewas refluxed for 8 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 separated by column chromatography (eluent: ethyl acetate: EtOH 9:1)

ORD record

ord-d4bd2c87ab7b4fae9b7b7266a0b6ed36

Source dataset

uspto-grants-2002_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06350756B1