Réaction #8210

Équation de réaction

benzenesulfonyl chloride

ICl

CH2Cl2

5,7-difluoroindole

→

N-Benzenesulfonyl-3-iodo-5,7-difluoroindole

Rendement 87.0%

Solvants

toluene

NaOH

toluene

pyridine

Conditions de réaction

Traitement

1. 1
   Lavagewashed with brine, 1N HCl, 1N NaOH
2. 2
   Séchagedried (Na2SO4)
3. 3
   Filtrationfiltered
4. 4
   Concentrationconcentrated
5. 5
   workup.STIRRINGThe crude 3-iodo-5,7-difluoroindole is stirred in toluene (85 ml)
6. 6
   workup.STIRRINGthe resulting mixture is stirred 24 hours
7. 7
   AutreThe two phase reaction mixture
8. 8
   Lavagewashed with brine, dried(Na2SO4)
9. 9
   Filtrationfiltered
10. 10
    Concentrationconcentrated
11. 11
    Autrethe residue is triturated with diethyl ether/petroleum ether
12. 12
    FiltrationThe resulting solid is filtered

Mode opératoire

The 1.0 M ICl in CH2Cl2 (43 ml, 43 mmol) is added to a solution of 5,7-difluoroindole (6 g, 39 mmol) in 35 ml pyridine under N2 at 0° C. and the resulting mixture is stirred for 30 minutes. The reaction is diluted with toluene and washed with brine, 1N HCl, 1N NaOH, dried (Na2SO4), filtered and concentrated. The crude 3-iodo-5,7-difluoroindole is stirred in toluene (85 ml) and 5 N NaOH (70 ml), tetrabutylammonium bromide (1.25 g, 3.9 mmol), then benzenesulfonyl chloride (6.2 ml, 48 mmol) are added and the resulting mixture is stirred 24 hours. The two phase reaction mixture is diluted with toluene, washed with brine, dried(Na2SO4), filtered, concentrated and the residue is triturated with diethyl ether/petroleum ether. The resulting solid is filtered to give 14.2 g of N-Benzenesulfonyl-3-iodo-5,7-difluoroindole (87%).

Source