Reaktion #2446276

Reaktionsgleichung

N-Iodosuccinimide

3-(5-Chloro-2-thienyl)-5-methyl-1H-pyrazole

sodium thiosulfate

sodium carbonate

→

3-(5-chloro-2-thienyl)-4-iodo-5-methyl-1H-pyrazole

Ausbeute 76.0%

Lösungsmittel

N,N-dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto warm to room temperature
2. 2
   FiltrationThe precipitate was filtered
3. 3
   Waschenwashed thoroughly with water
4. 4
   workup.DISSOLUTIONdissolved in ethyl acetate
5. 5
   Trocknendried over MgSO4
6. 6
   Filtrationfiltered
7. 7
   Sonstigeevaporated

Vorschrift

3-(5-Chloro-2-thienyl)-5-methyl-1H-pyrazole (40.3 mmol) was dissolved in 70 mL dry N,N-dimethylformamide and cooled to 0° C. under nitrogen atmosphere. N-Iodosuccinimide (42.7 mmol) was added in small portions at 0° C. The reaction mixture was allowed to warm to room temperature and was stirred overnight. The solution was poured into a mixture of saturated aqueous sodium thiosulfate solution and saturated aqueous sodium carbonate solution (1:1) at room temperature. The precipitate was filtered, washed thoroughly with water, dissolved in ethyl acetate, dried over MgSO4, filtered and evaporated to afford 9.9 g of 3-(5-chloro-2-thienyl)-4-iodo-5-methyl-1H-pyrazole (76% yield) that was used without further purification.

Quelle