Pyrazole → 3-chloro-6-(1H-pyrazol-1-yl)pyridazine

HRID 869137Notes

Reaction equation

HRID 869137 reaction equation
[NH:1]1[CH:5]=[CH:4][CH:3]=[N:2]1.[H-].[Na+].[Cl:8][C:9]1[N:10]=[N:11][C:12](Cl)=[CH:13][CH:14]=1>CN1C(=O)CCC1.O.C(OCC)(=O)C>[Cl:8][C:9]1[N:10]=[N:11][C:12]([N:1]2[CH:5]=[CH:4][CH:3]=[N:2]2)=[CH:13][CH:14]=1

Participants

7

Reactant 3

HCID 1048PyrazoleHCID 24758Sodium hydrideHCID 673313,6-Dichloropyridazine

Product 1

HCID 125628453-chloro-6-(1H-pyrazol-1-yl)pyridazineYield 86.2%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 8857Ethyl AcetateSolventHCID 13387N-methyl-2-pyrrolidoneSolvent

Procedure

To a solution of pyrazole (3.69 g, 25 mmol, 1.0 equiv) in NMP (25 mL) was added sodium hydride (60% dispersion in mineral oil, 1.5 g, 38 mmol, 1.5 equiv). The mixture was stirred for 15 min, followed by the addition of 3,6-dichloropyridazine (3.02 g, 25 mmol, 1.0 equiv). The reaction mixture was stirred for 1.5 h and then diluted with water (50 mL) and ethyl acetate (100 mL). After transferring to a separatory funnel and shaking, the organic layer was separated from the aqueous layer and then washed with brine (3×50 mL). The organic layer was then dried over Na2SO4, filtered, and concentrated to give 3.89 g of 3-chloro-6-(1H-pyrazol-1-yl)pyridazine as a crude tan solid that was used directly in the next step.

Workup

  1. stirringThe reaction mixture was stirred for 1.5 h
  2. customAfter transferring to a separatory funnel
  3. stirringshaking
  4. customthe organic layer was separated from the aqueous layer
  5. washwashed with brine (3×50 mL)
  6. dry with materialThe organic layer was then dried over Na2SO4
  7. filtrationfiltered
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-e0c9edbdc306489f94354771c7e762b7
Source dataset
uspto-grants-2015_03
Patent number
US08969346B2

Reaction notes

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