Water → (RS)-(2,6-difluoro-3-hydroxy-phenyl)-ethoxy-acetic acid

Temperatur

65 °C

To a solution of (RS)-[3-(tert-butyl-diphenyl-silanyloxy)-2,6-difluoro-phenyl]-ethoxy-acetic acid ethyl ester (62.5 g) in THF (250 ml) and MeOH (250 ml) was added H2O (200 ml) and LiOH.H2O (10.5 g) and it was stirred 2 h at 65° C. MeOH and THF were evaporated and the aqueous residue was washed with Hept/Et2O 9:1 (2×150 ml). The organic layers were extracted with two portions of H2O (200 ml). The combined aqueous layers were cooled in an ice bath and acidified with 35 ml 25% aq. HCl. Extraction with AcOEt (3×200 ml) followed by washing with brine, drying (Na2SO4) and evaporation of the solvent afforded 28.7 g (99%) of (RS)-(2,6-difluoro-3-hydroxy-phenyl)-ethoxy-acetic acid. Yellow viscous oil. MS 231.2 ([M−H]−).

1. customMeOH and THF were evaporated
2. washthe aqueous residue was washed with Hept/Et2O 9:1 (2×150 ml)
3. extractionThe organic layers were extracted with two portions of H2O (200 ml)
4. temperatureThe combined aqueous layers were cooled in an ice bath
5. extractionExtraction with AcOEt (3×200 ml)
6. washby washing with brine
7. customdrying
8. custom(Na2SO4) and evaporation of the solvent

ORD-Eintrag

ord-b5fe155d56594b88ba2bffe8f3974b7d

Quelldatensatz

uspto-grants-2006_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07129238B2