Hydrochloric Acid → p-Toluenesulfonic acid

HRID 396944Notes

Reaction equation

HRID 396944 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 174.2%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
1 °C

Procedure

80 ml of water and 60 g (0.592 mole) of 36% hydrochloric acid were placed in a 500-ml flask as a reactor, and cooled to 0 to 2° C. Thereto was dropwise added, at 0 to 5° C. with stirring, 96.0 g (0.112 mole) of an aqueous solution of a potassium salt of 2-amino-5-fluorothiophenol. The resulting mixture had a pH of 0.90. Further, 20.0 g (0.105 mole) of p-toluenesulfonic acid monohydrate was added. Thereto was dropwise added, at 16 to 20° C., a solution of D-alanine-N-carboxyanhydride (16.7 g, purity: 78.3%, 0.318 mole) dissolved in tetrahydrofuran (30 ml) (the solution was beforehand prepared at 16 to 20° C.). Aging was conducted at 15 to 20° C. for 4 hours. The resulting crystals were collected by filtration and dried at 60° C. to obtain 31.5 g of a p-toluenesulfonate of [2-(6-fluorobenzothiazolyl)]ethylamine (purity: 98.95%) (the yield was 75.5% relative to the potassium salt of 2-amino-5-fluorothiophenol).

Workup

  1. additionThereto was dropwise added, at 0 to 5° C.
  2. additionThereto was dropwise added, at 16 to 20° C.
  3. customwas beforehand prepared at 16 to 20° C.)
  4. filtrationThe resulting crystals were collected by filtration
  5. customdried at 60° C.

Sources & evidence

ORD record
ord-59038b25679d41f3b1264152b43796f4
Source dataset
uspto-grants-2003_08
Patent number
US06608207B2

Reaction notes

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