Thionyl Chloride → 5-Cyano-1-benzofuran-2-carbonyl chloride

HRID 1291020Notes

Reaction equation

HRID 1291020 reaction equation
S(Cl)([Cl:3])=O.[C:5]([C:7]1[CH:8]=[CH:9][C:10]2[O:14][C:13]([C:15](O)=[O:16])=[CH:12][C:11]=2[CH:18]=1)#[N:6]>>[C:5]([C:7]1[CH:8]=[CH:9][C:10]2[O:14][C:13]([C:15]([Cl:3])=[O:16])=[CH:12][C:11]=2[CH:18]=1)#[N:6]

Participants

3

Reactant 2

HCID 24386Thionyl ChlorideHCID 102360545-cyanobenzofuran-2-carboxylic Acid

Product 1

HCID 128136405-Cyano-1-benzofuran-2-carbonyl chloride

Procedure

Thionyl chloride (8 ml, 110 mmol) was added to 5-cyano-2-benzofurancarboxylic acid (1.00 g, 5.34 mmol) and the mixture was refluxed under heating for 30 minutes. Thionyl chloride was distilled away under reduced pressure and toluene (3 ml) was added which was again distilled away under reduced pressure to give 5-cyano-2-benzofurancarbonyl chloride. This was dissolved in toluene (20 ml) and pyridine (0.86 ml, 10.7 mmol), 4-dimethylaminopyridine (131 mg, 1.07 mmol) and t-butyl 4-hydroxycyclohexylacetate (1.35 g, 5.88 mmol) were added. The mixture was refluxed under heating for one hour. Water was added to the reaction mixture and the mixture was extracted with ethyl acetate. The extract was dried over anhydrous magnesium sulfate. After filtration, low boiling matters were distilled away from the filtrate under reduced pressure and the residue was purified by silica gel column chromatography (n-hexane/ethyl acetate=10/1-5/1) to give 1.12 g of t-butyl [4-[(5-cyano-2-benzofuranyl)carbonyloxy]cyclohexyloxy]acetate as a colorless solid (52%).

Workup

  1. temperaturethe mixture was refluxed
  2. temperatureunder heating for 30 minutes
  3. distillationThionyl chloride was distilled away under reduced pressure and toluene (3 ml)
  4. additionwas added which
  5. distillationwas again distilled away under reduced pressure

Sources & evidence

ORD record
ord-931facb382a14146a612f780beae180f
Source dataset
uspto-grants-1998_05
Patent number
US05753670

Reaction notes

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