Hydrochloric Acid → p-Toluenesulfonic acid

HRID 39394Notes

Reaction equation

HRID 39394 reaction equation
Cl.O.[C:3]1([CH3:13])[CH:8]=[CH:7][C:6]([S:9]([OH:12])(=[O:11])=[O:10])=[CH:5][CH:4]=1>CO>[C:3]1([CH3:13])[CH:4]=[CH:5][C:6]([S:9]([OH:12])(=[O:10])=[O:11])=[CH:7][CH:8]=1

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 521998p-Toluenesulfonic acid monohydrate

Product 1

HCID 6101p-Toluenesulfonic acidYield 185.1%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To 40 mL of methanol, 4.52 g (19.2 mmol) of the hydrochloric acid salt similarly produced and 3.65 g (19.2 mmol, 1.00 eq) of p-toluenesulfonic acid monohydrate were added. Dissolving under heating was made at 40 to 50° C., and methanol was concentrated under reduced pressure. Then, 27 mL of isopropanol and 6 mL of n-heptane were added to the residue, and dissolving under heating was made at 90° C., followed by gradually lowering the temperature to room temperature. Precipitated crystal was filtered and washed with a small amount of n-heptane, followed by being dried under vacuum, thereby obtaining 6.12 g of p-toluenesulfonic acid salt of α-trifluoromethyl-β-substituted-β-amino acids. The recovery was 86%. The diastereomer ratio was syn-body:anti-body=>98:2 according to 1H-NMR and 19F-NMR analyses.

Workup

  1. dissolutionDissolving
  2. temperatureunder heating
  3. customwas made at 40 to 50° C.
  4. concentrationmethanol was concentrated under reduced pressure
  5. additionThen, 27 mL of isopropanol and 6 mL of n-heptane were added to the residue
  6. dissolutiondissolving
  7. temperatureunder heating
  8. customwas made at 90° C.
  9. customto room temperature
  10. customPrecipitated crystal
  11. filtrationwas filtered
  12. washwashed with a small amount of n-heptane
  13. customby being dried under vacuum

Sources & evidence

ORD record
ord-b784f4654ebb4056b77790f6a78f7ba9
Source dataset
uspto-grants-2013_09
Patent number
US08524913B2

Reaction notes

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