Dichloromethane → 5,7-Difluoro-3-iodo-1-(phenylsulfonyl)-1H-indole

The 1.0 M ICl in CH2Cl2 (43 ml, 43 mmol) is added to a solution of 5,7-difluoro-indole (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%).

1. washwashed with brine, 1N HCl, 1N NaOH
2. dry with materialdried (Na2SO4)
3. filtrationfiltered
4. concentrationconcentrated
5. stirringThe crude 3-iodo-5,7-difluoroindole is stirred in toluene (85 ml)
6. stirringthe resulting mixture is stirred 24 hours
7. customThe two phase reaction mixture
8. washwashed with brine
9. dry with materialdried (Na2SO4)
10. filtrationfiltered
11. concentrationconcentrated
12. customthe residue is triturated with diethyl ether/petroleum ether
13. filtrationThe resulting solid is filtered

ORD record

ord-940f13e358e24caa9cd489bc6fd36e80

Source dataset

uspto-grants-2007_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07208505B2