反应详情

A mixture of 4-(1H-indazol-3-yl)-l-piperazinecarbonitrile (8.0 g, 40 mmol) and 25% H2SO4 (100 ml) was stirred at reflux for 4.5 hours. The reaction was cooled in an ice bath and made basic by the dropwise addition of 50% NaOH. The basic solution was extracted with ethyl acetate. The ethyl acetate was washed with H2O, dried with MgSO4, and concentrated to afford 5.2 g (73% of the desired compound, as a solid. The solid was recrystallized twice from toluene to afford 3.0 g of 3-(1-piperazinyl)-1H-indazole, m.p.=153°-155° C.

1. temperatureat reflux for 4.5 hours
2. temperatureThe reaction was cooled in an ice bath
3. extractionThe basic solution was extracted with ethyl acetate
4. washThe ethyl acetate was washed with H2O
5. dry with materialdried with MgSO4
6. concentrationconcentrated