Reacción #1005938

Ecuación de reacción

1-(4-chloro-phenyl)-3-((Z)-3-tributylstannanyl-but-2-enyloxy)-1H-pyrazole

iodine

→

1-(4-chlorophenyl)-3-[(Z)-3-iodobut-2-enoxy]pyrazole

Disolventes

methylene chloride

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroAfter removal of the solvents in vacuo the crude product
2. 2
   workup.DISSOLUTIONwas dissolved in 200 ml MTBE
3. 3
   workup.ADDITION100 ml 20% aqueous potassium fluoride solution have been added
4. 4
   workup.STIRRINGthe mixture was stirred for 2 h at ambient temperature
5. 5
   OtroThe aqueous layer was separated
6. 6
   Extracciónextracted with 20 ml methyl-tert.-butyl ether twice
7. 7
   LavadoThe combined organic phases have been washed twice with 20 ml of water each,
8. 8
   Secadodried with sodium sulfate
9. 9
   Otrothe solvents were removed in vacuo
10. 10
    OtroThe crude product (7.2 g) has been purified by chromatography on 50 g silica with methyl-tert.-butylether/hexane (1:20)

Procedimiento

To 10.0 g (18.6 mmol) 1-(4-chloro-phenyl)-3-((Z)-3-tributylstannanyl-but-2-enyloxy)-1H-pyrazole in 100 ml methylene chloride have been added 4.7 g (18.6 mmol) iodine at ambient temperature with stirring which was continued for 3 h. After removal of the solvents in vacuo the crude product was dissolved in 200 ml MTBE. 100 ml 20% aqueous potassium fluoride solution have been added and the mixture was stirred for 2 h at ambient temperature. The aqueous layer was separated and extracted with 20 ml methyl-tert.-butyl ether twice. The combined organic phases have been washed twice with 20 ml of water each, dried with sodium sulfate, and the solvents were removed in vacuo. The crude product (7.2 g) has been purified by chromatography on 50 g silica with methyl-tert.-butylether/hexane (1:20). Yield 5.9 g, melting point 75-77° C.

Fuente