Reaktion #2354371

Reaktionsgleichung

2-ethylpyrazolo[1,5-a]pyridine

sodium iodide

N-chlorosuccinimide

→

title compound

Ausbeute 99.1%

2-Ethyl-3-iodopyrazolo[1,5-a]pyridine

Ausbeute 99.1%

Lösungsmittel

ethyl acetate

water

water

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturunder cooling in an ice water bath
2. 2
   Extraktionthe resulting mixture was extracted with ethyl acetate
3. 3
   WaschenThe separated organic layer was washed twice with a 10% sodium thiosulfate aqueous solution
4. 4
   Einengenconcentrated under reduced pressure
5. 5
   workup.ADDITIONTo the resulting residue was added hexane
6. 6
   workup.DISSOLUTIONthe residue was dissolved
7. 7
   Temperaturwith heating
8. 8
   FiltrationThe hexane solution was filtrated
9. 9
   Sonstigeto remove an insoluble substance
10. 10
    WaschenThe hexane solution was washed with water
11. 11
    Einengenconcentrated under reduced pressure
12. 12
    workup.DISSOLUTIONThen, the resulting residue was dissolved in ethyl acetate
13. 13
    workup.DISTILLATIONthe solvent was distilled off under reduced pressure

Vorschrift

To a mixture of 2-ethylpyrazolo[1,5-a]pyridine (360 g, 2.46 mol), ethyl acetate (3600 mL), water (1800 mL) and sodium iodide (480 g, 3.20 mol, 1.3 equivalent) was added N-chlorosuccinimide (411 g, 3.08 mol) over a period of 30 minutes under cooling in an ice water bath, then, the reaction mixture was stirred at room temperature for 2 hours and 20 minutes. To the reaction mixture was added water and ethyl acetate, and the resulting mixture was extracted with ethyl acetate. The separated organic layer was washed twice with a 10% sodium thiosulfate aqueous solution, and concentrated under reduced pressure. To the resulting residue was added hexane, the residue was dissolved with heating. The hexane solution was filtrated to remove an insoluble substance. The hexane solution was washed with water, and concentrated under reduced pressure. Then, the resulting residue was dissolved in ethyl acetate, and the solvent was distilled off under reduced pressure, to obtain 663 g of a title compound (yield: 98.9%).

Quelle