反应详情

A mixture of 184 parts of ethyl trifluoroacetoacetate, 120 parts of phenylhydrazine, 200 parts by volume of ethanol and 20 parts by volume of 22° Be hydrochloric acid was heated under reflux, with stirring, for one hour, then 500 parts of water were added and the product was cooled in ice. The yellow precipitate obtained was filtered off, drained, washed, with a small portion of chilled toluene until decoloration took place. Thereafter it was dried in an oven (50° C.). 215 parts of 1-phenyl-3-trifluoromethyl-5-pyrazolone was obtained of which the melting point was 193° C.

1. temperaturewas heated
2. temperatureunder reflux
3. temperaturethe product was cooled in ice
4. customThe yellow precipitate obtained
5. filtrationwas filtered off
6. washwashed, with a small portion of chilled toluene until decoloration
7. customThereafter it was dried in an oven (50° C.)