Reaktion #1960509

Reaktionsgleichung

4-Fluorophenylhydrazine hydrochloride

3-methyl-2-butanone

indole

→

indole

Ausbeute 99.9%

5-fluoro Indole

Ausbeute 99.9%

Lösungsmittel

acetic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeto obtain the clear solution
2. 2
   SonstigeAt the end of 40 min.
3. 3
   workup.ADDITIONthe mixture was poured
4. 4
   ExtraktionThe residue was extracted into ethyl acetate (100 ml×2)
5. 5
   Waschenwashed with water (100 ml×2) and ethyl acetate layer
6. 6
   Trocknenwas dried over anhydrous sodium sulfate
7. 7
   FiltrationAfter filtration, ethyl acetate
8. 8
   Sonstigewas removed
9. 9
   Sonstigethe residue was dried

Vorschrift

A mixture containing 4-Fluorophenylhydrazine hydrochloride (5.0 g; 30.75 mmol; ALDRICH), 3-methyl-2-butanone (3.7 g; 43 mmol; ALDRICH) and acetic acid (30 ml) was stirred for 30 min. under nitrogen to obtain the clear solution. The mixture was then refluxed at 130° C. The appearance of UV-Vis Abs. Max at 255 nm and the disappearance of the peak at 282 nm confirmed the formation of the indole. At the end of 40 min. the reaction was stopped and the mixture was poured into crushed ice (100 g). The residue was extracted into ethyl acetate (100 ml×2), washed with water (100 ml×2) and ethyl acetate layer was dried over anhydrous sodium sulfate. After filtration, ethyl acetate was removed, and the residue was dried to give 4.15 g of the indole (Yield 76%).

Quelle