Hydrochloric Acid → 3-Fluoro-4-(2,2,2-trifluoroethoxy)benzoic acid

Temperature

50 °C

The above methoxy-4-trifluoroethoxy-5-fluorobenzoate (420 mg, 1.7 mmol) was dissolved in freshly distilled THF (50 mL) and water was added (20 mL) and 2N NaOH (2 mL) was dropped into the rapidly stirring solution at room temperature. The solution was warmed to 50° C. and stirred rapidly for 18 hours. The biphasic result was reduced to a smaller volume under reduced pressure and water was added to the aqueous residue to a volume of 50 mL and was then acidified with 4 N HCl to a pH of 1-2. The product was extracted with methylene chloride (3×50 mL). The combined organics were extracted with brine (50 mL) and the organic solvent was dried over MgSO4 and filtered and the solvent was removed under reduced pressure to give the desired 4-trifluoroethoxy-5-fluorobenzoic acid.

1. additionwas dropped into the rapidly stirring solution at room temperature
2. customThe biphasic result
3. additionwas added to the aqueous residue to a volume of 50 mL
4. extractionThe product was extracted with methylene chloride (3×50 mL)
5. extractionThe combined organics were extracted with brine (50 mL)
6. dry with materialthe organic solvent was dried over MgSO4
7. filtrationfiltered
8. customthe solvent was removed under reduced pressure

ORD record

ord-1e6b8897562d412183a40fa3b1ae7fd3

Source dataset

uspto-grants-1998_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05726172