Reaktion #8210

Reaktionsgleichung

benzenesulfonyl chloride

ICl

CH2Cl2

5,7-difluoroindole

→

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

Ausbeute 87.0%

Lösungsmittel

toluene

NaOH

toluene

pyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenwashed with brine, 1N HCl, 1N NaOH
2. 2
   Trocknendried (Na2SO4)
3. 3
   Filtrationfiltered
4. 4
   Einengenconcentrated
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
   SonstigeThe two phase reaction mixture
8. 8
   Waschenwashed with brine, dried(Na2SO4)
9. 9
   Filtrationfiltered
10. 10
    Einengenconcentrated
11. 11
    Sonstigethe residue is triturated with diethyl ether/petroleum ether
12. 12
    FiltrationThe resulting solid is filtered

Vorschrift

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%).

Quelle