Thionyl Chloride → Toluene-p-sulphonic anhydride

HRID 2054735Notes

Reaction equation

HRID 2054735 reaction equation
[OH2:1].[C:2]1([CH3:12])[CH:7]=[CH:6][C:5]([S:8]([OH:11])(=[O:10])=[O:9])=[CH:4][CH:3]=1.[S:13](Cl)(Cl)=[O:14]>CC1CCCCC1>[C:2]1([CH3:12])[CH:3]=[CH:4][C:5]([S:8]([O:11][S:13]([C:5]2[CH:6]=[CH:7][C:2]([CH3:12])=[CH:3][CH:4]=2)(=[O:14])=[O:1])(=[O:9])=[O:10])=[CH:6][CH:7]=1

Participants

4

Reactant 2

HCID 24386Thionyl ChlorideHCID 521998p-Toluenesulfonic acid monohydrate

Product 1

HCID 77773Toluene-p-sulphonic anhydrideYield 52.3%

Reagents, catalysts & solvents 1

HCID 7962MethylcyclohexaneSolvent

Conditions

Temperature
50 °C

Procedure

50.0 g (260 mmol) of p-toluenesulphonic acid monohydrate were suspended in 140 g of methylcyclohexane and heated to 50° C. with stirring. 99.9 g (831 mmol, 3.2 equivalents [eq.]) of thionyl chloride were then added dropwise over a period of 75 minutes at such a rate that moderate gas evolution was observed. After addition had ended, the mixture was stirred at 50° C. for a further 1 h. 20.1 g of excess thionyl chloride were then distilled off at a bottom temperature of 96° C. The residue was cooled to 5° C. and stirred at this temperature for 1 h. The precipitated solid was filtered off and washed with 50 ml of methylcyclohexane. After drying under reduced pressure, 22.2 g (52% of theory) of p-toluenesulphonic anhydride were isolated.

Workup

  1. additionAfter addition
  2. stirringthe mixture was stirred at 50° C. for a further 1 h
  3. distillation20.1 g of excess thionyl chloride were then distilled off at a bottom temperature of 96° C
  4. temperatureThe residue was cooled to 5° C.
  5. stirringstirred at this temperature for 1 h
  6. filtrationThe precipitated solid was filtered off
  7. washwashed with 50 ml of methylcyclohexane
  8. customAfter drying under reduced pressure

Sources & evidence

ORD record
ord-319e9b63be544caeb3a46af47df60706
Source dataset
uspto-grants-2008_02
Patent number
US07329779B2

Reaction notes

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