Trifluoroacetic acid → (3S, 5RS)-3,5-dimethyl-piperazin-2-one

HRID 1432903Notes

Reaction equation

HRID 1432903 reaction equation
C(OC(=O)[NH:7][C@H:8]([C:10](=[O:16])[NH:11][CH2:12][C:13](=O)[CH3:14])[CH3:9])(C)(C)C.FC(F)(F)C(O)=O>C(Cl)Cl>[CH3:9][C@@H:8]1[NH:7][CH:13]([CH3:14])[CH2:12][NH:11][C:10]1=[O:16]

Participants

4

Reactant 2

HCID 6422Trifluoroacetic acidHCID 53756530(1S)-[1-(2-oxo-propylcarbamoyl)-ethyl]-carbamic acid tertbutyl ester

Product 1

HCID 45092763(3S, 5RS)-3,5-dimethyl-piperazin-2-one

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

(1S)-[1-(2-oxo-propylcarbamoyl)-ethyl]-carbamic acid tertbutyl ester (5.93 g, 24.3 mmol) is stirred in a solution of 30% trifluoroacetic acid in methylene chloride (100 mL) for three hours. The solvents are removed in vacuo. The residue is dissolved in 50 mL of MeOH and transferred to a par bottle. Palladium on carbon (10%, 1.0 g) is added, and the mixture is hydrogenated under pressure for 24 hours. The catalyst is filtered off; the MeOH is removed in vacuo to afford (3S, 5RS)-3,5-dimethyl-piperazin-2-one which is directly protected with a benzyl carbamate without further purification.

Workup

  1. customThe solvents are removed in vacuo
  2. dissolutionThe residue is dissolved in 50 mL of MeOH
  3. additionPalladium on carbon (10%, 1.0 g) is added
  4. filtrationThe catalyst is filtered off
  5. customthe MeOH is removed in vacuo

Sources & evidence

ORD record
ord-76fbc2b841a6490e966a9f42e639f635
Source dataset
uspto-grants-2009_11
Patent number
US07612075B2

Reaction notes

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