p-Toluenesulfonic acid → HCID 66874385, compound

HRID 249911Notes

Reaction equation

HRID 249911 reaction equation
[CH3:1][NH:2][CH2:3][C@@H:4]([NH:6][C@@H:7]([CH3:12])[C:8](OC)=[O:9])[CH3:5].C1(C)C=CC(S(O)(=O)=O)=CC=1>C(O)C>[CH3:1][N:2]1[CH2:3][C@H:4]([CH3:5])[NH:6][C@@H:7]([CH3:12])[C:8]1=[O:9]

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 86623721HCID 86623721, compound

Product 1

HCID 66874385HCID 66874385, compoundYield 43%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

The crude (S)-methyl 2-((S)-1-(methylamino)propan-2-ylamino)propanoate was dissolved in ethanol (30 mL) and p-toluenesulfonic acid (175 mg) was added. The reaction mixture was heated to reflux for 18 h and then concentrated under reduced pressure. The residue was partitioned between CH2Cl2 (40 mL) and saturated NaHCO3 (20 mL). The aqueous layer was separated and extracted again with CH2Cl2 (20 mL). The combined organic layers were dried (Na2SO4) and concentrated under reduced pressure to give (3S,5S)-1,3,5-trimethylpiperazin-2-one (230 mg, 43% which contains 2,6-lutidine, ca 2:1 product:2,6-lutidine) as an amber oil. 1H NMR consistent.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureto reflux for 18 h
  3. concentrationconcentrated under reduced pressure
  4. customThe residue was partitioned between CH2Cl2 (40 mL) and saturated NaHCO3 (20 mL)
  5. customThe aqueous layer was separated
  6. extractionextracted again with CH2Cl2 (20 mL)
  7. dry with materialThe combined organic layers were dried (Na2SO4)
  8. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-a8259a527e684f1fab24d8903770c46c
Source dataset
uspto-grants-2011_01
Patent number
US07863271B2

Reaction notes

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