4-Toluenesulfonyl chloride → 2-(1-Benzofuran-5-yl)-5-methyl-1,3,4-oxadiazole

HRID 452606Notes

Reaction equation

HRID 452606 reaction equation
[C:1]([NH:4][NH:5][C:6]([C:8]1[CH:9]=[CH:10][C:11]2[O:15][CH:14]=[CH:13][C:12]=2[CH:16]=1)=[O:7])(=O)[CH3:2].C1(C)C=CC(S(Cl)(=O)=O)=CC=1>N1C=CC=CC=1.C(OCC)(=O)C>[O:15]1[C:11]2[CH:10]=[CH:9][C:8]([C:6]3[O:7][C:1]([CH3:2])=[N:4][N:5]=3)=[CH:16][C:12]=2[CH:13]=[CH:14]1

Participants

5

Reactant 2

HCID 73974-Toluenesulfonyl chlorideHCID 68664854N'-acetyl-1-benzofuran-5-carbohydrazide

Product 1

HCID 686643682-(1-Benzofuran-5-yl)-5-methyl-1,3,4-oxadiazoleYield 220.8%

Reagents, catalysts & solvents 2

HCID 1049PyridineSolventHCID 8857Ethyl AcetateSolvent

Procedure

A solution of N′-acetyl-1-benzofuran-5-carbohydrazide (20.7 g, 36.2 mmol) and p-toluenesulfonyl chloride (36.2 g, 190 mmol) in pyridine (200 mL) was stirred under an argon atmosphere at 80° C. for 16 hr. After cooling, the reaction mixture was diluted with ethyl acetate, washed water, 2 M hydrochloric acid, saturated aqueous sodium hydrogen carbonate solution and saturated brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by basic silica gel column chromatography (tetrahydrofuran) and recrystallized from tetrahydrofuran to give the title compound (16.0 g, yield 84%) as colorless crystals.

Workup

  1. temperatureAfter cooling
  2. washwashed water, 2 M hydrochloric acid, saturated aqueous sodium hydrogen carbonate solution and saturated brine
  3. dry with materialdried over anhydrous magnesium sulfate
  4. concentrationconcentrated under reduced pressure
  5. customThe residue was purified by basic silica gel column chromatography (tetrahydrofuran)
  6. customrecrystallized from tetrahydrofuran

Sources & evidence

ORD record
ord-74565f994e034cf78912fb3d9c0e088c
Source dataset
uspto-grants-2013_07
Patent number
US08492378B2

Reaction notes

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