Reaktion #47610

Reaktionsgleichung

lithium hydroxide monohydrate

(S)-4-(t-butyl-dimethyl-silanyloxy)-2-[4-(2-chloro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-butyric acid methyl ester

tetrahydrofuran

→

(S)-4-(t-butyl-dimethyl-silanyloxy)-2-[4-(2-chloro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-butyric acid

Ausbeute 81.0%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   EinengenAfter such time, the mixture was concentrated in vacuo
2. 2
   Sonstigeto remove the tetrahydrofuran
3. 3
   workup.ADDITIONdiluted with water (10 mL)
4. 4
   Extraktionextracted with ethyl acetate
5. 5
   SonstigeThe organic layers were then dried
6. 6
   Einengenconcentrated in vacuo

Vorschrift

A mixture of (S)-4-(t-butyl-dimethyl-silanyloxy)-2-[4-(2-chloro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-butyric acid methyl ester (250 mg, 0.57 mmol) in a 1:1 solution of tetrahydrofuran:water (8 mL) was treated with lithium hydroxide monohydrate (48 mg, 1.14 mmol) and stirred for 1.5 h at 25° C. After such time, the mixture was concentrated in vacuo to remove the tetrahydrofuran and diluted with water (10 mL) and the pH adjusted to pH=5 with 1N aqueous hydrochloric acid and extracted with ethyl acetate. The organic layers were then dried and concentrated in vacuo to afford (S)-4-(t-butyl-dimethyl-silanyloxy)-2-[4-(2-chloro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-butyric acid (195 mg, 81%) as an off-white foam: HR-ES-MS m/z calculated for C20H28NO5ClSi [M+H]+ 426.1498, observed 426.1498.

Quelle