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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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]−).

Herkunft & Nachweise