Sodium Hydroxide → 3-(Piperazin-1-YL)-1H-indazole

HRID 1781645Notes

Reaction equation

HRID 1781645 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[C:3]([N:10]2[CH2:15][CH2:14][N:13](C#N)[CH2:12][CH2:11]2)=[N:2]1.[OH-].[Na+]>OS(O)(=O)=O>[N:10]1([C:3]2[C:4]3[C:9](=[CH:8][CH:7]=[CH:6][CH:5]=3)[NH:1][N:2]=2)[CH2:15][CH2:14][NH:13][CH2:12][CH2:11]1

Participants

4

Procedure

A mixture of 4-(1H-indazol-3-yl)-1-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.

Workup

  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

Sources & evidence

ORD record
ord-90240f3c544f484abdfaef8b15e7133b
Source dataset
uspto-grants-1997_05
Patent number
US05633265

Reaction notes

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