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

HRID 1461827Notes

Reaction equation

HRID 1461827 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 of Example 13 (8.0 g, 0.04 mol) 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-657b528258be47ff902c6a8fcee7c3ed
Source dataset
uspto-grants-1991_12
Patent number
US05077405

Reaction notes

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