Pyrazole → 3-Chloro-2-(1H-pyrazol-1-yl)pyridine

HRID 251919Notes

Reaction equation

HRID 251919 reaction equation
[NH:1]1[CH:5]=[CH:4][CH:3]=[N:2]1.Cl[C:7]1[C:12]([Cl:13])=[CH:11][CH:10]=[CH:9][N:8]=1.C(=O)([O-])[O-].[Cs+].[Cs+].CN(C)C=O>O>[Cl:13][C:12]1[C:7]([N:1]2[CH:5]=[CH:4][CH:3]=[N:2]2)=[N:8][CH:9]=[CH:10][CH:11]=1

Participants

6

Reactant 4

HCID 1048PyrazoleHCID 6228DimethylformamideHCID 10796Cesium carbonateHCID 169882,3-Dichloropyridine

Product 1

HCID 446041173-Chloro-2-(1H-pyrazol-1-yl)pyridineYield 67.8%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
100 °C

Procedure

A mixture of 2 g of pyrazole, 4.34 g of 2,3-dichloropyridine, 9.58 g of cesium carbonate and 40 ml N,N-dimethylformamide was stirred at 100° C. for 8 hours. The reaction mixture was allowed to cool to room temperature, and water was added thereto. The mixture was extracted with methyl tert-butyl ether three times. The organic layers were combined, washed successively with water and an aqueous saturated sodium chloride solution, dried over magnesium sulfate, and concentrated under reduced pressure. The resulting residue was subjected to silica gel column chromatography to obtain 3.57 g of 3-chloro-2-(1H-pyrazol-1-yl)pyridine of the formula:

Workup

  1. temperatureto cool to room temperature
  2. extractionThe mixture was extracted with methyl tert-butyl ether three times
  3. washwashed successively with water
  4. dry with materialan aqueous saturated sodium chloride solution, dried over magnesium sulfate
  5. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-3f7f15b7b56240fb8987e93cb2569ee4
Source dataset
uspto-grants-2011_01
Patent number
US07867949B2

Reaction notes

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