Hydrochloric Acid → p-Toluenesulfinic acid

HRID 250735Notes

Reaction equation

HRID 250735 reaction equation
[Na+].[C:2]1([CH3:11])[CH:7]=[CH:6][C:5]([S:8]([O-:10])=[O:9])=[CH:4][CH:3]=1.Cl>O.COC(C)(C)C>[C:2]1([CH3:11])[CH:7]=[CH:6][C:5]([S:8]([OH:10])=[O:9])=[CH:4][CH:3]=1

Participants

5

Reactant 2

HCID 313Hydrochloric AcidHCID 2723791Sodium p-toluenesulfinate

Product 1

HCID 10818p-Toluenesulfinic acidYield 98.8%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 15413tert-Butyl methyl etherSolvent

Procedure

Treat a solution of p-toluenesulfinic acid sodium salt, (6.0 g, 33.7 mmol) in water (20 mL) and tert-butyl methyl ether (10 mL) dropwise with concentrated HCl (3 mL) and stir for 10 minutes. Separate the solution in a separatory funnel and wash the organic layer with saturated aqueous sodium chloride. Dry the organic over Na2SO4, filter, and remove the solvent to afford 5.2 g (quantitative) of p-toluenesulfinic acid. Combine the acid with benzaldehyde (2.4 g, 22.5 mmol), formamide (3.8 g, 84.2 mmol), and trimethylsilyl chloride (4.0 g, 37.0 mmol) in 30 mL of a 1:1 solution of toluene/acetonitrile. Heat the reaction to 50° C. and stir for 5 hours. Cool the reaction and dilute with water (100 mL) and tert-butyl methyl ether (30 mL). Cool the solution in an ice bath and filter to afford 4.5 g (70%) of desired product. Dry the solid under vacuum overnight to remove any residual water.

Workup

  1. customSeparate the solution in a separatory funnel
  2. washwash the organic layer with saturated aqueous sodium chloride
  3. dry with materialDry the organic over Na2SO4
  4. filtrationfilter
  5. customremove the solvent

Sources & evidence

ORD record
ord-b2d56c59c4ef4b45a4d5562a524e069b
Source dataset
uspto-grants-2011_01
Patent number
US07863310B2

Reaction notes

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