Réaction #5463

Équation de réaction

sodium hydride

indole-3-carboxylic acid

sodium hydroxide

Dimethylsulfate

→

colorless crystals

Rendement 75.3%

1-Methyl-1H-indole-3-carboxylic acid

Rendement 75.3%

Solvants

N,N-dimethylformamide

Conditions de réaction

Traitement

1. 1
   TempératureA cooled
2. 2
   Températurecooled
3. 3
   FiltrationThe suspension was filtered
4. 4
   Lavagethe wet solid was washed with water
5. 5
   Températurerefluxed for 30 minutes
6. 6
   Autrethe methanol was removed in vacuo
7. 7
   ExtractionThe aqueous solution was extracted with ether (50 mL)
8. 8
   FiltrationThe suspension was filtered
9. 9
   Lavagethe solid was washed with water
10. 10
    Séchagedried exhaustively m vacuo in the presence of Drierite
11. 11
    AutreRecrystallization from acetonitrile

Mode opératoire

A cooled (0° C.) suspension of 60% sodium hydride-oil dispersion (0.96 g, 24 mmol) in anhydrous N,N-dimethylformamide (15 mL) under nitrogen was treated in portions with indole-3-carboxylic acid (1.62 g, 10 mmol), and the mixture was stirred at 45°±5° C. for 30 minutes. Dimethylsulfate (3.03 g, 24 mmol) was added, and the mixture was heated to 100° C. for 30 minutes, cooled, and added to ice water (100 mL). The suspension was filtered and the wet solid was washed with water and taken up in 50% aqueous methanol (40 mL). The mixture was treated with 50% aqueous sodium hydroxide (3.0 g, 37.5 mmol) and refluxed for 30 minutes, then the methanol was removed in vacuo and replaced with water. The aqueous solution was extracted with ether (50 mL), then acidified with 3N HCl to pH 3 (15 mL). The suspension was filtered and the solid was washed with water and dried exhaustively m vacuo in the presence of Drierite. Recrystallization from acetonitrile afforded 1.32 g (75%) of colorless crystals; mp 201°-202° C. (dec).

Source