Reaktion #5449

Reaktionsgleichung

H2O

Potassium t-butoxide

ethyl -4-(2-bromo-5-methoxy phenyl)butyrate

diethyl oxalate

→

desired product

Ausbeute 89.0%

2-Oxo-3-carboethoxy-5-(2-bromo-5-methoxyphenyl)pentanoic acid ethyl ester

Ausbeute 89.0%

Lösungsmittel

ether

ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe aqueous layer was separated
2. 2
   Extraktionextracted with ether
3. 3
   TrocknenThe ether layer was dried (MgSO4)
4. 4
   Sonstigethe solvent was evaporated

Vorschrift

Potassium t-butoxide (26.94 g) was suspended in 130 ml of anhydrous ether and cooled to 0° C. A solution of 60.24 g ethyl -4-(2-bromo-5-methoxy phenyl)butyrate and 43.84 g diethyl oxalate in 60 ml ether was added dropwise over 20 min. After 2 h at 25° C., the reaction was poured into 400 ml H2O and the aqueous layer was separated, acidified to pH 1 and extracted with ether. The ether layer was dried (MgSO4) and the solvent was evaporated to yield 71.26 g of the desired product as a colorless oil (89%). NMR (CDCl3) δ 1.25 (t, 3H), 1.4 (t, 3H), 2.25 (m, 2H), 2.75 (m, 2H), 3.78 (s, 3H), 4.0-4.5 (m, 5H), 6.64 (dd, 1H), 6.79 (d, 1H), 7.40 (d, 1H).

Quelle