HCID 20255250, compound → 1-(2-Methoxyphenyl)-1-oxo-1lambda~5~-piperazine

HRID 463722Notes

Reaction equation

HRID 463722 reaction equation
C([CH:5]1[CH2:10][N+:9]([O-:19])([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=2[O:17][CH3:18])[CH2:8][CH2:7][N:6]1C([O-])=O)(C)(C)C>FC(F)(F)C(O)=O>[CH3:18][O:17][C:12]1[CH:13]=[CH:14][CH:15]=[CH:16][C:11]=1[N+:9]1([O-:19])[CH2:8][CH2:7][NH:6][CH2:5][CH2:10]1

Participants

3

Reactant 1

HCID 20255250HCID 20255250, compound

Product 1

HCID 135605501-(2-Methoxyphenyl)-1-oxo-1lambda~5~-piperazineYield 74.4%

Reagents, catalysts & solvents 1

HCID 6422Trifluoroacetic acidSolvent

Procedure

To a stirred ice cold solution of 260 ml trifluoroacetic acid there was added under nitrogen, 26 g of tert-butyl-4-(2-methoxyphenyl)-1-piperazinecarboxylate 4-oxide and stirred for another 6 hours at ambient temperature. The solvent was removed in vacuo. The slurry was taken up in 200 ml ether and extracted twice with each 150 ml of water. The aqueous solution was applied to a column packed with 500 g Dowex 2 (×4, 20-50 mesh, OH- form) and the N-oxide-base eluted with water. After evaporation of the solvent in vacuo, the white foam (18.6 g) was dissolved in a minumum of methylene chloride and the base precipitated by addition of diisopropylether to give 13.1 g colorless hygroscopic crystals of 1-(2-methoxyphenyl)piperazine 1-oxide, mp 157°-160°. The dihydrochloride was crystallized from ethanol/ether, mp 192°-194°.

Workup

  1. customThe solvent was removed in vacuo
  2. extractionextracted twice with each 150 ml of water
  3. washthe N-oxide-base eluted with water
  4. customAfter evaporation of the solvent in vacuo
  5. dissolutionthe white foam (18.6 g) was dissolved in a minumum of methylene chloride
  6. customthe base precipitated by addition of diisopropylether

Sources & evidence

ORD record
ord-242bc0218b494e81bd459c7c1e6cdc85
Source dataset
uspto-grants-1985_10
Patent number
US04544657

Reaction notes

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