Reaktion #47334

Reaktionsgleichung

(S)-2-[4-(3-chloro-2-fluoro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-4-methyl-pentanoic acid methyl ester

lithium hydroxide monohydrate

→

(S)-2-[4-(3-chloro-2-fluoro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-4-methyl-pentanoic acid

Ausbeute 90.0%

Lösungsmittel

tetrahydrofuran

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted with diethyl ether (1×75 mL)
2. 2
   Extraktionextracted with ethyl acetate (3×50 mL)
3. 3
   TrocknenThe combined organics were dried over magnesium sulfate
4. 4
   Filtrationfiltered
5. 5
   Waschenrinsed with ethyl acetate
6. 6
   Einengenconcentrated in vacuo

Vorschrift

A mixture of (S)-2-[4-(3-chloro-2-fluoro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-4-methyl-pentanoic acid methyl ester (0.87 g, 2.46 mmol) in tetrahydrofuran (15 mL) and water (5 mL) was treated with lithium hydroxide monohydrate (0.12 g, 2.85 mmol). The reaction was stirred at 25° C. for 2.5 h. At this time, the reaction was diluted with water (75 mL) and extracted with diethyl ether (1×75 mL). The aqueous layer was acidified with a 2N aqueous hydrochloric acid solution and then extracted with ethyl acetate (3×50 mL). The combined organics were dried over magnesium sulfate, filtered, rinsed with ethyl acetate and concentrated in vacuo to afford (S)-2-[4-(3-chloro-2-fluoro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-4-methyl-pentanoic acid (0.75 g, 90%) as a light orange solid: HR-ES-MS m/z calculated for C16H17NO4FCl [M+H]+ 342.0903, observed 342.0904; 1H NMR (400 MHz, DMSO-d6) δ ppm 0.87 (d, J=6.5 Hz, 3H), 0.93 (d, J=6.5 Hz, 3H), 1.35-1.56 (m, 1H), 1.56-1.70 (m, 1H), 1.72-1.86 (m, 1H), 4.19 (d, J=18.2 Hz, 1H), 4.29 (d, J=18.2 Hz, 1H), 4.63 (dd, J=11.5, 4.3 Hz, 1H), 5.05 (s, 1H), 7.33 (td, J=8.3, 1.4 Hz, 1H), 7.49-7.55 (m, 1H), 7.57 (ddd, J=8.3, 6.8, 1.4 Hz, 1H), 12.92 (br. s., 1H).

Quelle