Pyrazole → 1-Tosylpyrozole

HRID 1785164

Reaction equation

HRID 1785164 reaction equation
[NH:1]1[CH:5]=[CH:4][CH:3]=[N:2]1.Cl[CH2:7]Cl.[C:9]1(C)[C:10]([S:15](Cl)(=[O:17])=[O:16])=[CH:11][CH:12]=[CH:13][CH:14]=1>N1C=CC=CC=1>[CH3:7][C:13]1[CH:14]=[CH:9][C:10]([S:15]([N:1]2[CH:5]=[CH:4][CH:3]=[N:2]2)(=[O:16])=[O:17])=[CH:11][CH:12]=1

Participants

5

Reactant 3

HCID 1048PyrazoleHCID 6344DichloromethaneHCID 8623o-Toluenesulfonyl chloride

Product 1

HCID 3207501-TosylpyrozoleYield 76%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

To a solution of pyrazole (2 g, 29.0 mmol), dichloromethane (20 ml) and pyridine (5 ml) was added 4 toluene sulphonyl chloride (6.89 g, 36 mmol) and the reaction mixture stirred at ambient temperature for 1 hour. The reaction mixture was partitioned between dichlormethane and an aqueous solution of sodium bicarbonate. The organic layer was separated, dried over magnesium sulfate and evaporated under reduced pressure. The residue as purified by flash chromatography on silica eluting with a mixture of 70-100% dichloromethane in hexane and then 10% ethyl acetate in dichloromethane to give the product as a white solid (4.9 g, 76%). NMR Spectrum: (CDCl3) 2.43 (s, 3H), 6.39 (m, 1H), 7.34 (d, 2H), 7.72 (d, 1H), 7.89 (d, 2H), 8.10 (d, 1H). Mass Spectrum: M+H+ 223 and M+H− 221.

Workup

  1. customThe reaction mixture was partitioned between dichlormethane
  2. customThe organic layer was separated
  3. dry with materialdried over magnesium sulfate
  4. customevaporated under reduced pressure
  5. customThe residue as purified by flash chromatography on silica eluting with a mixture of 70-100% dichloromethane in hexane

Sources & evidence

ORD record
ord-e8715fbe9663403b87216859031940bb
Source dataset
uspto-grants-2009_03
Patent number
US07504408B2

Linked notes

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