Reacción #1909

Ecuación de reacción

product

3-cyano-4-trifluoromethylsulfenyl-5-(N-trifluoroacetylamino)pyrazole

ammonium hydroxide

hydrochloric acid

→

title compound

Rendimiento 87.6%

3-cyano-4-trifluoromethylsulfenyl-5-aminopyrazole

Rendimiento 87.6%

Disolventes

methanol

ethyl acetate

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturathe solution was refluxed for 3 hours
2. 2
   LavadoThe organic layer was washed several times with water and brine
3. 3
   Secadodried over MgSO4
4. 4
   Concentraciónconcentrated to dryness
5. 5
   Otroto give an oily brown residue which
6. 6
   Otrowas recrystallized from methyl tert-butyl ether

Procedimiento

The product of Step E (55 g, 181 mmoles) was dissolved in methanol. 100 ml of ammonium hydroxide were added, the solution was refluxed for 3 hours and then stirred at room temperature for 15 hours. The methanolic solution was brought to pH7 using concentrated aqueous hydrochloric acid and diluted with ethyl acetate. The organic layer was washed several times with water and brine, dried over MgSO4 and concentrated to dryness to give an oily brown residue which was recrystallized from methyl tert-butyl ether to afford 33 g of the title compound, m.p. around 187° C.

Fuente