Hydrochloric Acid → p-Toluenesulfinic acid

HRID 2252017Notes

Reaction equation

HRID 2252017 reaction equation
Cl.[Na+].[C:3]1([CH3:12])[CH:8]=[CH:7][C:6]([S:9]([O-:11])=[O:10])=[CH:5][CH:4]=1>O.COC(C)(C)C>[C:3]1([CH3:12])[CH:8]=[CH:7][C:6]([S:9]([OH:11])=[O:10])=[CH:5][CH:4]=1

Participants

5

Reactant 2

HCID 313Hydrochloric AcidHCID 2723791Sodium p-toluenesulfinate

Product 1

HCID 10818p-Toluenesulfinic acid

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 15413tert-Butyl methyl etherSolvent

Procedure

Add concentrated hydrochloric acid (3 mL) dropwise to a solution of p-toluene-sulfinic acid sodium salt in water (20 mL) and tert-butyl methyl ether (10 mL). Stir for 10 minutes and then separate the layers. Wash the organic layer with saturated aqueous sodium chloride, dry over sodium sulfate and concentrate under reduced pressure to provide 5 g of p-toluenesulfinic acid. Combine this acid with benzaldehyde (4.75 g, 44.8 mmol), formamide (4.9 g, 0.11 mol), and camphorsulfonic acid (0.86 g, 3.7 mmol) and heat to 60° C. for 18 hours. Remove the reaction from the heat and slurry the white solid in 3:1 hexanes:methanol. Filter the slurry to provide 7.6 g (82%) of the desired product as a white solid. 1H-NMR (DMSO-d6): § 9.75 (d, 1H), 7.98 (s, 1H), 7.69 (d, 2H), 7.53 (d 2H), 7.39 (m, 5H), 6.36 (d, 1H), 2.38 (s, 1H).

Workup

  1. customseparate the layers
  2. washWash the organic layer with saturated aqueous sodium chloride
  3. dry with materialdry over sodium sulfate
  4. concentrationconcentrate under reduced pressure

Sources & evidence

ORD record
ord-3697339b6880430e82008861156b6db1
Source dataset
uspto-grants-2008_01
Patent number
US07320995B2

Reaction notes

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