Dabco → 4,4-Diphenyl-2-butanone

HRID 1198034Notes

Reaction equation

HRID 1198034 reaction equation
C(OC(=O)[CH2:5][C:6](=[O:21])[CH2:7][CH:8]([C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)[C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)C.N12CCN(CC1)CC2>Cl>[C:15]1([CH:8]([C:9]2[CH:10]=[CH:11][CH:12]=[CH:13][CH:14]=2)[CH2:7][C:6](=[O:21])[CH3:5])[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=1

Participants

4

Reactant 2

HCID 9237DabcoHCID 15105219beta-Oxo-delta-phenyl-benzene pentanoic acid ethyl ester

Product 1

HCID 794214,4-Diphenyl-2-butanoneYield 70%

Reagents, catalysts & solvents 1

HCID 313Hydrochloric AcidSolvent

Procedure

To a solution of β-oxo-δ-phenyl-benzene pentanoic acid ethyl ester (8.0 g, 0.026 mol) in 47.5 mL xylenes (15.0 eq), 1,4-diazabicyclo[2.2.2]octane (30.28 g, 0.269 mol, 10 eq) was added and the reaction mixture was first heated to reflux for 5 hours and then stirred at room temperature for 16 hours (D. H. Miles, et al, J. Org. Chem. 39, 2647 (1974)). The reaction mixture was then acidified (pH 1) with approximately 10 mL 5% HCl. This heterogeneous mixture was then filtered through Celite, thoroughly washing the bed of Celite with ether. The organic layer was washed with water, dried (MgSO4), and concentrated in vacuo to give a crude oil. Purification by flash chromatography (silica gel, 15% EtOAc/hexane) yielded 4.0 g (0.018 mol, 70%) of the desired product.

Workup

  1. temperaturethe reaction mixture was first heated
  2. temperatureto reflux for 5 hours
  3. filtrationThis heterogeneous mixture was then filtered through Celite
  4. washthoroughly washing the bed of Celite with ether
  5. washThe organic layer was washed with water
  6. dry with materialdried (MgSO4)
  7. concentrationconcentrated in vacuo
  8. customto give a crude oil
  9. customPurification by flash chromatography (silica gel, 15% EtOAc/hexane)

Sources & evidence

ORD record
ord-cff587fa76454e11bfabdbe78f5d5e5f
Source dataset
uspto-grants-1994_01
Patent number
US05278326

Reaction notes

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