反应详情

12 g (0.042 mol) of 5-amino-4-cyano-1-(2-chloro-4-trifluoromethoxy-phenyl)-pyrazole are boiled under reflux with 5 g of Raney nickel in 50 ml of 75% strength aqueous formic acid for 1 hour; the still warm solution is filtered under suction, the residue is rinsed with water, the filtrate is extracted several times with ether, and the combined ether phases are washed with saturated sodium bicarbonate solution, dried over sodium sulphate and evaporated down in vacuo. 8.0 g (62% of theory) of 5-amino-1-(2-chloro-4-trifluoromethoxy-phenyl)-4-formylpyrazole are obtained in the form of an oil.

1. filtrationthe still warm solution is filtered under suction
2. washthe residue is rinsed with water
3. extractionthe filtrate is extracted several times with ether
4. washthe combined ether phases are washed with saturated sodium bicarbonate solution
5. dry with materialdried over sodium sulphate
6. customevaporated down in vacuo