Trifluoroacetic acid → 1-(2-Chloro-5-fluorophenyl)-5,5-dimethylpiperazin-2-one

HRID 1694932Notes

Reaction equation

HRID 1694932 reaction equation
FC(F)(F)C(O)=O.C(OC([N:15]1[CH2:20][C:19](=[O:21])[N:18]([C:22]2[CH:27]=[C:26]([F:28])[CH:25]=[CH:24][C:23]=2[Cl:29])[CH2:17][C:16]1([CH3:31])[CH3:30])=O)(C)(C)C>C(Cl)Cl>[Cl:29][C:23]1[CH:24]=[CH:25][C:26]([F:28])=[CH:27][C:22]=1[N:18]1[CH2:17][C:16]([CH3:30])([CH3:31])[NH:15][CH2:20][C:19]1=[O:21]

Participants

4

Reactant 2

HCID 6422Trifluoroacetic acidHCID 666454974-(2-Chloro-5-fluorophenyl)-2,2-dimethyl-5-oxopiperazine-1-carboxylic acid t-butyl ester

Product 1

HCID 666453991-(2-Chloro-5-fluorophenyl)-5,5-dimethylpiperazin-2-oneYield 89%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

4.2 ml of trifluoroacetic acid (54.7 mmol) was added to a solution of 1.80 g of 4-(2-chloro-5-fluorophenyl)-2,2-dimethyl-5-oxopiperazine-1-carboxylic acid t-butyl ester obtained in Example (62c) (5.47 mmol) in methylene chloride (8.4 ml) at room temperature, and the mixture was stirred at the same temperature for 30 minutes. The reaction mixture was concentrated under reduced pressure. A saturated sodium bicarbonate aqueous solution was added, followed by extraction with methylene chloride. Then, the organic layer was dried over anhydrous magnesium sulfate. After filtration, the solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (elution solvent:methylene chloride/methanol=10/1) to obtain 1.25 g of the title compound (yield: quant.).

Workup

  1. concentrationThe reaction mixture was concentrated under reduced pressure
  2. additionA saturated sodium bicarbonate aqueous solution was added
  3. extractionfollowed by extraction with methylene chloride
  4. dry with materialThen, the organic layer was dried over anhydrous magnesium sulfate
  5. filtrationAfter filtration
  6. customthe solvent was evaporated under reduced pressure
  7. customthe residue was purified by silica gel column chromatography (elution solvent:methylene chloride/methanol=10/1)

Sources & evidence

ORD record
ord-e2a91d173d8343a480f6e3555234c980
Source dataset
uspto-grants-2012_04
Patent number
US08158790B2

Reaction notes

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