Reaktion #1334556

Reaktionsgleichung

AcOEt

(RS)-(2,6-difluoro-4-trifluoromethanesulfonyloxy-phenyl)-ethoxy-acetic acid ethyl ester

2-(trimethylsilyl)ethanol

triethylamine

→

(RS)-4-(ethoxy-ethoxycarbonyl-methyl)-3,5-difluoro-benzoic acid 2-trimethylsilanyl-ethyl ester

Ausbeute 76.0%

Lösungsmittel

DMSO

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenit was washed with 1 N HCl (2×40 ml), water (2×40 ml) and brine (30 ml)
2. 2
   TrocknenAfter drying (MgSO4) the solvent
3. 3
   Sonstigewas evaporated

Vorschrift

To a solution of (RS)-(2,6-difluoro-4-trifluoromethanesulfonyloxy-phenyl)-ethoxy-acetic acid ethyl ester (200 mg) and 2-(trimethylsilyl)ethanol (603 mg) in DMSO (2.5 ml) was added triethylamine (1.8 ml) followed by Pd(OAc)2 (6 mg) and 1,3-bis(diphenylphosphino)propane (11 mg). The flask was put under carbon monoxide and the reaction mixture was stirred 2 h at 70° C. AcOEt (30 ml) was added and it was washed with 1 N HCl (2×40 ml), water (2×40 ml) and brine (30 ml). After drying (MgSO4) the solvent was evaporated. CC (Hept/AcOEt 98:2) afforded 151 mg (76%) of (RS)-4-(ethoxy-ethoxycarbonyl-methyl)-3,5-difluoro-benzoic acid 2-trimethylsilanyl-ethyl ester. Colorless oil. MS 406.6 ([M+NH4]+).

Quelle