Reaktion #1973914

Reaktionsgleichung

8-chloro-9-(2-Fluoroethyl)-5-methoxy-2,3,4,9-tetrahydro-1H-carbazole-4-carboxylic acid ethyl ester

9-(2-Fluoroethyl)-5-methoxy-2,3,4,9-tetrahydro-1H-carbazole-4-carboxylic acid ethyl ester

sodium hydroxide

→

9-(2-Fluoroethyl)-5-methoxy-2,3,4,9-tetrahydro-1H-carbazole-4-carboxylic acid

Ausbeute 99.3%

Lösungsmittel

ethanol

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   TemperaturThe reaction mixture was heated
3. 3
   Temperaturto reflux overnight
4. 4
   SonstigeThe solvent was removed in vacuo
5. 5
   workup.ADDITIONthe crude mixture diluted with water
6. 6
   Waschenwashed with dichloromethane
7. 7
   Trocknendried over magnesium sulfate
8. 8
   Einengenconcentrated in vacuo

Vorschrift

8-chloro-9-(2-Fluoroethyl)-5-methoxy-2,3,4,9-tetrahydro-1H-carbazole-4-carboxylic acid ethyl ester (16) (380 mg, 1.2 mmol) was dissolved in ethanol (4 mL). A solution of sodium hydroxide (580 mg, 14.5 mmol) dissolved in 6 mL of water, was added. The reaction mixture was heated to reflux overnight. The solvent was removed in vacuo and the crude mixture diluted with water, acidified with 2 N HCl until acidic, and washed with dichloromethane. The organics were combined and dried over magnesium sulfate and concentrated in vacuo to give 347 mg (quantitative) of 9-(2-Fluoroethyl)-5-methoxy-2,3,4,9-tetrahydro-1H-carbazole-4-carboxylic acid (17) as an off white solid which was used crude into the next step. The structure was confirmed by 13C NMR (75 MHz; CDCl3): δC 20.4, 21.9, 27.2, 39.9, 43.3 (d, JCF=23 Hz), 55.1, 81.9 (d, JCF=173 Hz), 100.3, 102.8, 106.2, 117.1, 122.2, 135.6, 137.8, 153.3, and 180.8.

Quelle