反应详情

Ethyl 2-(2,6-dichloro-4-trifluoromethylphenylazo)-4-chloroacetoacetate (52.7 g) was dissolved in ethanol (650 ml) and heated to reflux. Potassium acetate (11.2 g) was added portionwise and the reaction mixture was boiled for 1 hour and allowed to cool, and the solvent was evaporated. The residue was dissolved in dichloromethane (500 ml), washed with water (2×150 ml), dried over magnesium sulfate, filtered and evaporated. The residue was triturated with hexane, filtered and dried to give 3-carboethoxy-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-hydroxypyrazole (34.0 g) as a light brown solid, m.p. 140°-143° C.

1. temperatureheated to reflux
2. temperatureto cool
3. customthe solvent was evaporated
4. dissolutionThe residue was dissolved in dichloromethane (500 ml)
5. washwashed with water (2×150 ml)
6. dry with materialdried over magnesium sulfate
7. filtrationfiltered
8. customevaporated
9. customThe residue was triturated with hexane
10. filtrationfiltered
11. customdried