Reaktion #47259

Reaktionsgleichung

diethyl ether

(S)-2-[4-(2,6-difluoro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-4-methyl-pentanoic acid methyl ester

lithium hydroxide

→

(S)-2-[4-(2,6-difluoro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-4-methyl-pentanoic acid

Ausbeute 82.4%

Lösungsmittel

water

tetrahydrofuran

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter addition
2. 2
   Sonstigethe layers separated
3. 3
   Extraktionextracted with ethyl acetate (3×30 mL)
4. 4
   WaschenThe combined ethyl acetate fractions were washed with a saturated sodium chloride solution
5. 5
   Trocknendried over magnesium sulfate
6. 6
   Filtrationfiltered
7. 7
   Einengenconcentrated

Vorschrift

To a stirred mixture of (S)-2-[4-(2,6-difluoro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-4-methyl-pentanoic acid methyl ester (900 mg, 2.65 mmol) in tetrahydrofuran (10 mL) and water (3 mL) was added lithium hydroxide (135 mg, 3.19 mmol). After addition was complete the mixture was stirred at 25° C. for 2 h. The reaction mixture was poured into water and diethyl ether and the layers separated. The aqueous layer was made acidic with 2N aqueous hydrochloric acid and extracted with ethyl acetate (3×30 mL). The combined ethyl acetate fractions were washed with a saturated sodium chloride solution, dried over magnesium sulfate, filtered and concentrated to afford (S)-2-[4-(2,6-difluoro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-4-methyl-pentanoic acid (710 mg, 82%) as a yellow solid: LR-ES-MS m/z calculated for C16H17F2NO4 [M]+ 325, observed [M+H]+ 326.

Quelle