Trifluoroacetic acid methylene chloride → 1-(2-Phenyl-1-piperazinyl)ethanone

HRID 530627Notes

Reaction equation

HRID 530627 reaction equation
C(OC([N:8]1[CH2:13][CH2:12][N:11]([C:14](=[O:16])[CH3:15])[CH:10]([C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)[CH2:9]1)=O)(C)(C)C.C(O)(C(F)(F)F)=O.ClCCl>C1COCC1>[C:17]1([CH:10]2[CH2:9][NH:8][CH2:13][CH2:12][N:11]2[C:14](=[O:16])[CH3:15])[CH:18]=[CH:19][CH:20]=[CH:21][CH:22]=1

Participants

4

Reactant 2

HCID 21863450Trifluoroacetic acid methylene chlorideHCID 67083964(+/-)-1-BOC-4-acetyl-3-phenyl-piperazine

Product 1

HCID 231987601-(2-Phenyl-1-piperazinyl)ethanoneYield 119.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 4-acetyl-3-phenyl-piperazine-1-carboxylic acid tert-butyl ester (250 mg, 0.82 mmol) in THF (3 mL) at 0° C. was added 50% TFA/dichloromethane (1 mL). After stirred for 2 h, the reaction mixture was concentrated in vacuo. The residue was diluted with dichloromethane and silica-bound carbonate (2 g, 0.77 mmol/g, Silicycle, Inc.) was added. The reaction mixture was stirred overnight, filtered, and concentrated in vacuo. The residue was purified by flash chromatography (10/1 dichloromethane/methanol with 1% triethyl amine) to provide 1-(2-phenyl-piperazin-1-yl)-ethanone (200 mg, 119%). (M+H)+=205 m/e.

Workup

  1. concentrationthe reaction mixture was concentrated in vacuo
  2. additionThe residue was diluted with dichloromethane and silica-bound carbonate (2 g, 0.77 mmol/g, Silicycle, Inc.)
  3. additionwas added
  4. stirringThe reaction mixture was stirred overnight
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customThe residue was purified by flash chromatography (10/1 dichloromethane/methanol with 1% triethyl amine)

Sources & evidence

ORD record
ord-8da7e0cb58cd4eedbe282aa7ffabb9b7
Source dataset
uspto-grants-2016_05
Patent number
US09353096B2

Reaction notes

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