反应详情

A solution of (1-chloro-2-methylpropylidene)methane-1,1-dicarbonitrile (9.4 g, 61 mmol) in THF (250 mL) was treated with 2,6-dichlorophenylhydrazine hydrochloride (13.0 g, 61 mmol) followed by triethylamine (12.3 g, 122 mmol). The reaction was then heated to reflux for 18 h. The reaction was then cooled to room temp and partitioned between EtOAc (150 mL) and 1N NaOH (100 mL). The aqueous layer was extracted with EtOAc (2×150 mL) and the combined organic layers were washed with 10% aq. citric acid (150 mL), sat. aq. NaHCO3 (150 mL), and brine (150 mL). The organic layer was dried (MgSO4), filtered, and evaporated. The crude product was recrystallized from EtOAc/hexane to yield the desired pyrazole (11.2 g, 62%).

1. temperatureThe reaction was then heated
2. temperatureto reflux for 18 h
3. custompartitioned between EtOAc (150 mL) and 1N NaOH (100 mL)
4. extractionThe aqueous layer was extracted with EtOAc (2×150 mL)
5. washthe combined organic layers were washed with 10% aq. citric acid (150 mL), sat. aq. NaHCO3 (150 mL), and brine (150 mL)
6. dry with materialThe organic layer was dried (MgSO4)
7. filtrationfiltered
8. customevaporated
9. customThe crude product was recrystallized from EtOAc/hexane