Reaktion #507643

Reaktionsgleichung

N-[2-(4-bromophenylamino)phenyl]benzamide

xylene

ethyl acetate

p-toluenesulfonic acid

(4-bromophenyl)-(2-nitrophenyl)amine

→

1-(4-bromophenyl)-2-phenyl-1H-benzimidazole

Ausbeute 52.0%

Lösungsmittel

water

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwhile refluxing
2. 2
   Temperaturwith heating for 3 hours
3. 3
   workup.ADDITIONwere added to the reacted solution
4. 4
   Sonstigeby separating an insoluble substance
5. 5
   Filtrationby filtration
6. 6
   ExtraktionExtracting an organic layer from mother liquor
7. 7
   Waschenthe organic layer was washed with water
8. 8
   Trocknena saturated solution of sodium chloride and then, dried with anhydrous sodium sulfate
9. 9
   Sonstigeby removing the solvent
10. 10
    workup.DISTILLATIONby distillation under reduced pressure

Vorschrift

Suspending 2.1 g (5.7 mmol) of N-[2-(4-bromophenylamino)phenyl]benzamide obtained in the above step (2) into 30 milliliter of xylene, and adding 0.6 g (2.9 mmol) of p-toluenesulfonic acid 1 hydrate, the resultant solution was azeotropically dehydrated while refluxing with heating for 3 hours. After naturally cooling the reacted solution, ethyl acetate, dichloromethane and water were added to the reacted solution, followed by separating an insoluble substance by filtration. Extracting an organic layer from mother liquor, the organic layer was washed with water and a saturated solution of sodium chloride and then, dried with anhydrous sodium sulfate, followed by removing the solvent by distillation under reduced pressure. Refining the residue with silicagel column chromatography, 1.0 g of 1-(4-bromophenyl)-2-phenyl-1H-benzimidazole was obtained as white crystals with a slight pink color (yield: 52%).

Quelle