p-Toluenesulfonic acid → Pipecolic Acid

HRID 1274437Notes

Reaction equation

HRID 1274437 reaction equation
C([N:4]1[CH2:12][CH2:11][CH2:10][CH2:9][C@@H:5]1[C:6]([OH:8])=[O:7])(=O)C.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[NH:4]1[CH2:12][CH2:11][CH2:10][CH2:9][CH:5]1[C:6]([OH:8])=[O:7]

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 22883843HCID 22883843, compound

Product 1

HCID 849Pipecolic Acid

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

(R)-N-acetylpipecolic acid was placed in 10 volumes of toluene and heated, with stirring, to reflux. On attaining reflux, a catalytic amount of 4-toluenesulphonic acid was added to the solution which was then left to reflux for two hours with stirring. After this time had elapsed, the toluene was removed by rotary evaporation. To the residual solid was added 10 volumes of distilled water; this was then extracted with methyl ethyl ketone (MEK) (3×10 vols) to leave the sulphonic acid in the aqueous layer with any pipecolic acid formed. The MEK extracts were then concentrated down to a solid on the rotary evaporator to give racemic-N-acetylpipecolic acid, with 97% recovery.

Workup

  1. temperatureheated
  2. temperatureto reflux
  3. temperatureOn attaining reflux
  4. waitwas then left
  5. temperatureto reflux for two hours
  6. stirringwith stirring
  7. customthe toluene was removed by rotary evaporation
  8. additionTo the residual solid was added 10 volumes of distilled water
  9. extractionthis was then extracted with methyl ethyl ketone (MEK) (3×10 vols)

Sources & evidence

ORD record
ord-90769f0ba5da4acbb51b271894e87051
Source dataset
uspto-grants-2000_12
Patent number
US06156900

Reaction notes

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