Piperazine → 3-(Piperazin-1-YL)-1H-indazole

HRID 2211908Notes

Reaction equation

HRID 2211908 reaction equation
Cl[C:2]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[NH:4][N:3]=1.[NH:11]1[CH2:16][CH2:15][NH:14][CH2:13][CH2:12]1>>[N:11]1([C:2]2[C:10]3[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=3)[NH:4][N:3]=2)[CH2:16][CH2:15][NH:14][CH2:13][CH2:12]1

Participants

3

Reactant 2

HCID 4837PiperazineHCID 958943-Chloro-1H-indazole

Product 1

HCID 148234453-(Piperazin-1-YL)-1H-indazole

Conditions

Temperature
250 °C

Procedure

A neat mixture of 3-chloroindazole (15.72 g, 0.103 mol) and piperazine (46.00 g, 0.534 mol) was heated at 250° C. for 14 h in a stainless steel sealed vessel Upon cooling to room temperature, the viscous residue was partitioned between 1.0 N aqueous NaOH and methylene chloride. The organic layer was dried over magnesium sulfate, filtered, and the filtrate treated with 4.1 N HCl in dioxane which resulted in the precipitation of both products as a greenish-yellow gummy residue. The gum was collected and taken up in water where it was observed that the disubstituted piperazine precipitated out of solution. The precipitate was filtered off and the filtrate was concentrated in vacuo to give exclusively the monosubstituted piperazine, 3-piperazin-1-yl-1H-indazole, as a green foam. Yield, 19.03 g (77%). MS (APCI): 203 [M+H]+, 201 [M-H]−.

Workup

  1. temperatureUpon cooling to room temperature
  2. customthe viscous residue was partitioned between 1.0 N aqueous NaOH and methylene chloride
  3. dry with materialThe organic layer was dried over magnesium sulfate
  4. filtrationfiltered
  5. additionthe filtrate treated with 4.1 N HCl in dioxane which
  6. customresulted in the precipitation of both products as a greenish-yellow gummy residue
  7. customThe gum was collected
  8. customprecipitated out of solution
  9. filtrationThe precipitate was filtered off
  10. concentrationthe filtrate was concentrated in vacuo

Sources & evidence

ORD record
ord-319e0ebb42ed4a4bbdbd6b987c59b9be
Source dataset
uspto-grants-2006_09
Patent number
US07101886B2

Reaction notes

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