Iodine → 5-iodo-1-tosyl-1H-pyrazole

HRID 1785165Notes

Reaction equation

HRID 1785165 reaction equation
[CH3:1][C:2]1[CH:7]=[CH:6][C:5]([S:8]([N:11]2[CH:15]=[CH:14][CH:13]=[N:12]2)(=[O:10])=[O:9])=[CH:4][CH:3]=1.C([Li])(C)(C)C.CCCCC.[I:26]I.[Cl-].[NH4+]>C1COCC1>[I:26][C:15]1[N:11]([S:8]([C:5]2[CH:6]=[CH:7][C:2]([CH3:1])=[CH:3][CH:4]=2)(=[O:10])=[O:9])[N:12]=[CH:13][CH:14]=1

Participants

7

Reactant 5

HCID 807IodineHCID 8003PentaneHCID 25517Ammonium ChlorideHCID 3207501-TosylpyrozoleHCID 178418306HCID 178418306, compound

Product 1

HCID 159327945-iodo-1-tosyl-1H-pyrazoleYield 30.6%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of 1-[(4-methylphenyl)sulfonyl]-1H-pyrazole (2.0 g, 9.0 mmol) in THF (50 ml) was cooled to −78 C under a nitrogen atmosphere. To this was added tert butyl lithium (5.9 ml) in pentane (1.7M, 10 mmol). After 10 minutes iodine (2.53 g, 10 mmol) in THF (10 ml) was added and the reaction mixture was stirred for a further 30 minutes before allowing to warm to ambient temperature followed by stirring for 12 hours. A saturated solution of ammonium chloride was added and the mixture was partitioned between water and ethyl acetate. The organic layer was separated, dried over magnesium sulfate and evaporated under reduced pressure. The residue was purified by flash chromatography on silica eluting with a mixture of 20-100% dichloromethane in hexane to give the product as a solid (0.96 g, 30%).

Workup

  1. stirringby stirring for 12 hours
  2. customthe mixture was partitioned between water and ethyl acetate
  3. customThe organic layer was separated
  4. dry with materialdried over magnesium sulfate
  5. customevaporated under reduced pressure
  6. customThe residue was purified by flash chromatography on silica eluting with a mixture of 20-100% dichloromethane in hexane

Sources & evidence

ORD record
ord-0045a542e99440d9bdd0be7f9c396df2
Source dataset
uspto-grants-2009_03
Patent number
US07504408B2

Reaction notes

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