Trifluoroacetic acid → p-Toluenesulfonic acid

HRID 1766955Notes

Reaction equation

HRID 1766955 reaction equation
C(=O)([O-])[O-].[Cs+].[Cs+].C(Br)C1C=CC=CC=1.C(O)(C(F)(F)F)=O.O.[C:23]1([CH3:33])[CH:28]=[CH:27][C:26]([S:29]([OH:32])(=[O:31])=[O:30])=[CH:25][CH:24]=1>C(O)C.O.CN(C=O)C>[S:29]([OH:32])([C:26]1[CH:27]=[CH:28][C:23]([CH3:33])=[CH:24][CH:25]=1)(=[O:31])=[O:30]

Participants

8

Reactant 4

HCID 6422Trifluoroacetic acid2×HCID 7498Benzyl BromideHCID 10796Cesium carbonateHCID 521998p-Toluenesulfonic acid monohydrate

Product 1

HCID 6101p-Toluenesulfonic acid

Reagents, catalysts & solvents 3

HCID 702EthanolSolventHCID 962WaterSolvent2×HCID 6228DimethylformamideSolvent

Procedure

Ten (10) g of Boc-(13C-Leu)-OH.H2O was dissolved in ethanol (50 ml)-water (20 ml) and 6.52 g of cesium carbonate dissolved in 20 ml of distilled water was added. After concentration under reduced pressure, ethanol and toluene were added and the remaining water was azeotropically removed out to yield a gel product, which was suspended in 300 ml of DMF. To the suspension, 5.2 ml of benzyl bromide was added dropwise at room temperature while being stirred. After stirring at room temperature for 45 minutes, the solvent was distilled out under reduced pressure. Ethyl acetate was added and washed with water. After drying over anhydrous sodium sulfate, ethyl acetate was distilled out under reduced pressure to yield an oily product. To the product, 59 ml of TFA was added and stirred at room temperature for 40 minutes. After adding 8.37 g of p-toluenesulfonic acid monohydrate, TFA was distilled out under reduced pressure. Diisopropyl ether was added to the residue to crystallize to yield TosOH.H-(13C-Leu)-OBzl.

Workup

  1. additionwas added
  2. concentrationAfter concentration under reduced pressure, ethanol and toluene
  3. additionwere added
  4. customthe remaining water was azeotropically removed out
  5. customto yield a gel product, which
  6. stirringAfter stirring at room temperature for 45 minutes
  7. distillationthe solvent was distilled out under reduced pressure
  8. additionEthyl acetate was added
  9. washwashed with water
  10. dry with materialAfter drying over anhydrous sodium sulfate, ethyl acetate
  11. distillationwas distilled out under reduced pressure
  12. customto yield an oily product
  13. stirringstirred at room temperature for 40 minutes
  14. distillationwas distilled out under reduced pressure
  15. additionDiisopropyl ether was added to the residue
  16. customto crystallize

Sources & evidence

ORD record
ord-cce4fe3067bf402d9d06bd9b737ea0d9
Source dataset
uspto-grants-2007_06
Patent number
US07232559B1

Reaction notes

Loading…