1-Bromo-2-methylpropane → 1-Methyl-3-(2-methylpropyl)-4-(phenylmethyl)piperazinone

HRID 1413722Notes

Reaction equation

HRID 1413722 reaction equation
C([Li])CCC.[CH3:6][N:7]1[CH2:12][CH2:11][N:10]([CH2:13][C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[CH2:9][C:8]1=[O:20].C(NC(C)C)(C)C.Br[CH2:29][CH:30]([CH3:32])[CH3:31]>C1COCC1.C(OCC)(=O)C.CN(P(N(C)C)(N(C)C)=O)C>[CH3:6][N:7]1[CH2:12][CH2:11][N:10]([CH2:13][C:14]2[CH:15]=[CH:16][CH:17]=[CH:18][CH:19]=2)[CH:9]([CH2:29][CH:30]([CH3:32])[CH3:31])[C:8]1=[O:20]

Participants

8

Reactant 4

HCID 65551-Bromo-2-methylpropaneHCID 7912DiisopropylamineHCID 135204104-Benzyl-1-methylpiperazin-2-oneHCID 178418339Butyllithium

Product 1

HCID 233196871-Methyl-3-(2-methylpropyl)-4-(phenylmethyl)piperazinone

Reagents, catalysts & solvents 3

HCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolventHCID 12679HexamethylphosphoramideSolvent

Procedure

Butyl lithium (8.0 ml. of 1.6 M in hexane, 0.012 mole) is added at -60° to a stirred solution of 1-methyl-4-(phenylmethyl)piperazinone (Example 46, 2.04 g., 0.010 mole), diisopropylamine (1.1 g., 0.011 mole) and hexamethylphosphorotriamide (2.0 ml.) in THF (25 ml.). The solution is allowed to warm to 20°-25°, 1-bromo-2-methylpropane (4.1 g., 0.030 mole) is added and the solution is refluxed for 3 hours. The THF is removed under reduced pressure and the residual oil is partitioned between chloroform and water. Evaporation of the chloroform gives an oil which is dissolved in ethyl acetate and chromatographed on silica gel. Elution of the column with ethyl acetate and pooling of the appropriate fractions gives the title compound.

Workup

  1. temperatureto warm to 20°-25°
  2. temperaturethe solution is refluxed for 3 hours
  3. customThe THF is removed under reduced pressure
  4. customthe residual oil is partitioned between chloroform and water
  5. customEvaporation of the chloroform
  6. customgives an oil which
  7. customchromatographed on silica gel
  8. washElution of the column with ethyl acetate and pooling of the appropriate fractions

Sources & evidence

ORD record
ord-dd762bf3637846d0be197c4a4a49360e
Source dataset
uspto-grants-1981_02
Patent number
US04251438

Reaction notes

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