Réaction #1929006

Équation de réaction

sulfuric acid

dimethylamine

5,6-dichloroindole

sodium chloride

formaldehyde

→

5,6-dichlorogramine

Solvants

DMF

water

DMF

Conditions de réaction

Traitement

1. 1
   Températureis maintained at below 10° C
2. 2
   workup.STIRRINGThe mixture is stirred for an additional 15 minutes
3. 3
   Températurecooled to 0-5° C
4. 4
   workup.STIRRINGstirred for an additional hour at 0-5° C
5. 5
   Températureto warm to room temperature
6. 6
   workup.STIRRINGstirred for 24 hrs
7. 7
   workup.ADDITIONThe mixture is then added to a reactor
8. 8
   workup.ADDITIONActivated carbon next is added
9. 9
   workup.STIRRINGthe mixture stirred for 30 minutes
10. 10
    FiltrationUpon filtration
11. 11
    FiltrationThe precipitate is filtered
12. 12
    Lavagewashed with water until pH=7-8
13. 13
    Autrecentrifuged, and dried

Mode opératoire

Next, 37% aqueous formaldehyde solution and DMF are added into a reactor. The reactor is cooled to 0-5° C. and 33% aqueous dimethylamine solution then is added slowly with stirring. Concentrated sulfuric acid is added slowly to the mixture while the temperature is maintained at below 10° C. The mixture is stirred for an additional 15 minutes and cooled to 0-5° C. A solution of 5,6-dichloroindole (C) in DMF is added slowly to the reactor and stirred for an additional hour at 0-5° C. The mixture is allowed to warm to room temperature and stirred for 24 hrs. The mixture is then added to a reactor containing a solution of industrial sodium chloride in water. Activated carbon next is added and the mixture stirred for 30 minutes. Upon filtration, the filtrate is adjusted to pH>12 with 20% aqueous sodium hydroxide solution. The precipitate is filtered, washed with water until pH=7-8, centrifuged, and dried to yield crude 5,6-dichlorogramine (D). Recrystallization in 70% ethanol produces the pure product with melting point of 150-154° C.

Source