Hydrochloric Acid → p-Toluenesulfonic acid

HRID 396946Notes

Reaction equation

HRID 396946 reaction equation
Cl.[K].NC1C=CC(F)=CC=1S.O.[C:13]1([CH3:23])[CH:18]=[CH:17][C:16]([S:19]([OH:22])(=[O:21])=[O:20])=[CH:15][CH:14]=1>O1CCCC1.O>[CH3:23][C:13]1[CH:18]=[CH:17][C:16]([S:19]([OH:22])(=[O:21])=[O:20])=[CH:15][CH:14]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 3205472-Amino-5-fluorobenzene-1-thiolHCID 521998p-Toluenesulfonic acid monohydrateHCID 5462222Potassium

Product 1

HCID 6101p-Toluenesulfonic acidYield 199.1%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
3 °C

Procedure

80 ml of water and 60 g (0.592 mole) of 36% hydrochloric acid were placed in a 300-ml flask as a reactor, and cooled to 3° C. Thereto was dropwise added, at 2 to 5° C. with stirring, 96 g (0.112 mole) of an aqueous solution of a potassium salt of 2-amino-5-fluorothiophenol, followed by stirring for 1 hour. The system had a pH of 5.23. Thereto were added 20 g (0.105 mole) of p-toluenesulfonic acid monohydrate and 30 ml of tetrahydrofuran, followed by stirring for 30 minutes. Thereto was added 16.7 g (0.114 mole) of D-alanine-N-carboxyanhydride (purity: 78.3%) at 0° C. The resulting mixture was aged at 15 to 20° C. for 18 hours. The resulting crystals were collected by filtration and dried at 60° C. to obtain 36.0 g of a p-toluenesulfonate of [2-(6-fluorobenzothiazolyl)]ethylamine (purity: 95.2%) (the yield was 82.8% relative to the potassium salt of 2-amino-5-fluorothiophenol).

Workup

  1. additionThereto was dropwise added, at 2 to 5° C.
  2. stirringby stirring for 1 hour
  3. stirringby stirring for 30 minutes
  4. filtrationThe resulting crystals were collected by filtration
  5. customdried at 60° C.

Sources & evidence

ORD record
ord-d0a4496ccaca4900b9e56720e30ab8c2
Source dataset
uspto-grants-2003_08
Patent number
US06608207B2

Reaction notes

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