反应详情

A mixture of 6.3 parts of 2-(4-chloro-2-fluorophenyl)-1,4,5,6-tetrahydrocyclopentapyrazol-3(2H)-one, 7.9 parts of phosphorous oxybromide, 3.7 parts of N,N-diethylaniline and 10 parts of N,N-dimethylformamide was refluxed 24 hours and poured into 100 parts of water. After neutralizing with 50% aqueous sodium hydroxide solution, the mixture was extracted twice with 100 parts of diethyl ether. The ether extract was dried over anhydrous magnesium sulfate and the solvent was removed under a reduced pressure of 100 mm. Hg at ambient temperature. The crude product was recrystallized from ethanol-water to yield 2.1 parts of 3-bromo-2-(4-chloro-2-fluorophenyl)-2,4,5,6-tetrahydrocyclopentapyrazole melting at 106°-110°.

1. temperaturewas refluxed 24 hours
2. extractionthe mixture was extracted twice with 100 parts of diethyl ether
3. extractionThe ether extract
4. dry with materialwas dried over anhydrous magnesium sulfate
5. customthe solvent was removed under a reduced pressure of 100 mm. Hg at ambient temperature
6. customThe crude product was recrystallized from ethanol-water