Ethylenediamine → 2-Piperazinone, 3,3-dimethyl-

HRID 43136

Reaction equation

HRID 43136 reaction equation
C(O[C:4](=[O:9])[C:5](Br)([CH3:7])[CH3:6])C.[CH2:10]([NH2:13])[CH2:11][NH2:12].C(=O)([O-])[O-].[K+].[K+]>C1(C)C=CC=CC=1>[CH3:7][C:5]1([CH3:6])[NH:13][CH2:10][CH2:11][NH:12][C:4]1=[O:9]

Participants

5

Reactant 3

HCID 3301EthylenediamineHCID 11430Potassium CarbonateHCID 11745Propanoic acid, 2-bromo-2-methyl-, ethyl ester

Product 1

HCID 2111572-Piperazinone, 3,3-dimethyl-Yield 65.6%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A mixture of ethyl-2-bromoisobutyrate (14.6 g, 74.9 mmol), ethylene diamine (33 mL, 487 mmol, 6.5 equiv) and potassium carbonate (11.4 g, 82.4 mmol, 1.1 equiv) in toluene (150 mL) was stirred for 22 h at reflux, cooled and filtered. The filtrate was concentrated and the residue triturated in Et2O to afford 6.3 g of 3,3-dimethyl-piperazin-2-one as a white solid. Methyl iodide (4 mL, 64.0 mmol, 1.3 equiv) was added dropwise to a suspension of 3,3-dimethyl-piperazin-2-one (6.3 g, 49.2 mmol) and potassium carbonate (8.8 g, 64.0 mmol, 1.3 equiv) in DME (20 mL). The reaction mixture was heated to 45° C., stirred for 3 h, cooled and filtered, washing the filter cake with DME. The filtrate was concentrated and the residue triturated in DME to afford 2.8 g (batch 1) of the title compound as a white solid. The filtrate from the trituration was concentrated and the residue purified by silica gel column chromatography (DCM/MeOH, 9:1) to afford 1.75 g (batch 2) of the title compound as a white solid. Title compound: ESI-MS: 143.1 [M+H]+; TLC: Rf=0.25 (DCM/MeOH, 9:1).

Workup

  1. temperatureat reflux
  2. temperaturecooled
  3. filtrationfiltered
  4. concentrationThe filtrate was concentrated
  5. customthe residue triturated in Et2O

Sources & evidence

ORD record
ord-e901742aa3bc4db58580aec9d1ab2a9d
Source dataset
uspto-grants-2013_09
Patent number
US08536175B2

Linked notes

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