Sodium Iodide → 2-Ethyl-3-iodopyrazolo[1,5-a]pyridine

HRID 347858Notes

Reaction equation

HRID 347858 reaction equation
ClN1C(=O)CCC1=O.[CH2:9]([C:11]1[CH:19]=[C:14]2[CH:15]=[CH:16][CH:17]=[CH:18][N:13]2[N:12]=1)[CH3:10].[I-:20].[Na+]>C(OCC)(=O)C.O>[CH2:9]([C:11]1[C:19]([I:20])=[C:14]2[CH:15]=[CH:16][CH:17]=[CH:18][N:13]2[N:12]=1)[CH3:10]

Participants

6

Reactant 3

HCID 5238Sodium IodideHCID 31398ChlorosuccinimideHCID 161162612-Ethylpyrazolo[1,5-a]pyridine

Product 1

HCID 161149332-Ethyl-3-iodopyrazolo[1,5-a]pyridineYield 99.1%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 8857Ethyl AcetateSolvent3×

Procedure

N-Chlorosuccinimide (411 g, 3.08 mol) was gradually added to a mixture of 2-ethylpyrazolo[1,5-a]pyridine (360 g, 2.46 mol), ethyl acetate (3600 mL), water (1800 mL) and sodium iodide (480 g, 3.20 mol, 1.3 equivalents) over a period of 30 minutes while cooling with ice, and then the reaction mixture was stirred for 2 hours and 20 minutes at room temperature. After the reaction, water and ethyl acetate were added to the reaction mixture and extraction was performed with ethyl acetate. The organic extract was washed twice with 10% aqueous sodium thiosulfate, and then concentrated. Hexane was added to the residue, the mixture was heated to dissolution and the resulting solution was filtered to remove insoluble residue. After then washing the hexane solution with water, the hexane layer was concentrated, the residue was dissolved in ethyl acetate and the solvent was evaporated to afford 663 g of the title compound (98.9% yield).

Workup

  1. temperaturewhile cooling with ice
  2. additionwere added to the reaction mixture and extraction
  3. extractionThe organic extract
  4. washwas washed twice with 10% aqueous sodium thiosulfate
  5. concentrationconcentrated
  6. additionHexane was added to the residue
  7. temperaturethe mixture was heated to dissolution
  8. filtrationthe resulting solution was filtered
  9. customto remove insoluble residue
  10. washAfter then washing the hexane solution with water
  11. concentrationthe hexane layer was concentrated
  12. dissolutionthe residue was dissolved in ethyl acetate
  13. customthe solvent was evaporated

Sources & evidence

ORD record
ord-c7dd837d22394699abfd808b14375e33
Source dataset
uspto-grants-2007_02
Patent number
US07176216B2

Reaction notes

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