반응 #74171

반응 방정식

isobutyl bromide

N-[3-(4-bromo-1H-pyrazol-3-yl)-2,4-difluorophenyl]-2,5-difluorobenzene-sulfonamide

isobutyl bromide

→

N-{3-[4-bromo-1-(2-methyl propyl)-1H-pyrazol-5-yl]-2,4-difluorophenyl}-2,5-difluoro-benzenesulfonamide

용매

dichloromethane

sodium hydroxide

반응 조건

후처리

1. 1
   workup.STIRRINGafter 18 h additional stirring the reaction
2. 2
   기타The phases were separated
3. 3
   세척the organic layer was washed with water
4. 4
   건조dried over anhydrous sodium sulfate
5. 5
   농축concentrated
6. 6
   기타The crude residue was purified by flash chromatography (eluant: dichloromethane)

실험 절차

To the residue, dissolved in dichloromethane (10 mL), isobutyl bromide (1 mL, 9 mmol) and tetrabutylammonium bromide (0.16 g, 0.5 mmol) in 7 N sodium hydroxide (10 mL) were added and the mixture was vigorously stirred at room temperature. After 2 h, only N-[3-(4-bromo-1H-pyrazol-3-yl)-2,4-difluorophenyl]-2,5-difluorobenzene-sulfonamide was present. Upon addition of more isobutyl bromide (3 mL, 27 mmol) and tetrabutylammonium bromide (0.45 g, 1.4 mmol) and after 18 h additional stirring the reaction was completed. The phases were separated and the organic layer was washed with water, dried over anhydrous sodium sulfate and concentrated. The crude residue was purified by flash chromatography (eluant: dichloromethane). First the regioisomer N-{3-[4-bromo-1-(2-methyl propyl)-1H-pyrazol-5-yl]-2,4-difluorophenyl}-2,5-difluoro-benzenesulfonamide (0.065 g, 0.13 mmol) was isolated, then the title product was obtained as a white solid (0.12 g, 0.2 mmol, 15% four steps).

출처