Allyl bromide → 1-(2-Propenyl)-4-tert-butyloxycarbonyl-2-piperazinone

HRID 1162807Notes

Reaction equation

HRID 1162807 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][NH:11][C:10](=[O:14])[CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[CH2:15](Br)[CH:16]=[CH2:17].[H-].[Na+]>CN(C=O)C>[CH2:17]([N:11]1[CH2:12][CH2:13][N:8]([C:6]([O:5][C:1]([CH3:4])([CH3:2])[CH3:3])=[O:7])[CH2:9][C:10]1=[O:14])[CH:16]=[CH2:15]

Participants

5

Reactant 3

HCID 7841Allyl bromideHCID 24758Sodium hydrideHCID 3157178Tert-butyl 3-oxopiperazine-1-carboxylate

Product 1

HCID 544523841-(2-Propenyl)-4-tert-butyloxycarbonyl-2-piperazinone

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a stirred solution of 4-tert-butyloxycarbonyl-2-piperazinone (10 g, 50 mmol) and allyl bromide (7.25 g, 60 mmol) in DMF (75 mL) at 0° C. was added sodium hydride (2.4 g of a 60% suspension in mineral oil, 60 mmol) in portions over a period of 10 min. The mixture was allowed to warm to ambient temperature and stirred for 18 h. The solvent was removed in vacuo and the residue was partitioned between EtOAc and water. The EtOAc layer was dried (MgSO4), filtered, and the solvent was removed in vacuo. The residue was purified by silica gel column chromatography using a gradient elution of 33%, 40%, 50%, 60% EtOAc in hexanes. Concentration of product-containing fractions in vacuo gave the title compound as an oil. HPLC RT=2.80 min (Method A), ES MS (M+H)=241, 1H NMR (400 MHz, CDCl3) δ 5.76 (ddt, 1H), 5.2 (overlapping doublets, 2H), 4.10 (s, 2H), 4.04 (d, J=6 Hz, 2H), 3.64 (t, J=7 Hz, 2 H), 3.50 (t, J=7 Hz, 2H), 1.47, (s, 9H).

Workup

  1. customThe solvent was removed in vacuo
  2. customthe residue was partitioned between EtOAc and water
  3. dry with materialThe EtOAc layer was dried (MgSO4)
  4. filtrationfiltered
  5. customthe solvent was removed in vacuo
  6. customThe residue was purified by silica gel column chromatography
  7. washa gradient elution of 33%, 40%, 50%, 60% EtOAc in hexanes

Sources & evidence

ORD record
ord-13e0a4bf2b2c4655bb3b603c82f22a0a
Source dataset
uspto-grants-2010_10
Patent number
US07820680B2

Reaction notes

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