Acetone → 2,4-Pentanedione, 1-phenyl-

HRID 873433Notes

Reaction equation

HRID 873433 reaction equation
[C:1]1([CH2:7][C:8]([O:10]CC)=O)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[CH3:13][C:14]([CH3:16])=[O:15].Cl>CCOCC>[C:1]1([CH2:7][C:8](=[O:10])[CH2:13][C:14](=[O:15])[CH3:16])[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

5

Reactant 3

HCID 180AcetoneHCID 313Hydrochloric AcidHCID 7590Ethyl phenylacetate

Product 1

HCID 187232,4-Pentanedione, 1-phenyl-Yield 69.3%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

To a solution of NaNH2 (19.02 g, 480 mmol) in anhydrous ether (400 mL) under N2 at −5° C. was added dropwise ethyl phenylacetate (19.2 g, 150 mmol) and then acetone (21.23 g, 370 mmol) with vigorous stirring. After addition, the reaction mixture was stirred at room temperature overnight. The mixture was then acidified to pH 4.0-5.0 with 1N HCl. The organic layer was separated and concentrated in vacuo. The crude product was purified by silica gel chromatography to give 1-phenyl-2,4-pentanedione (18.32 g, 44%). 1H NMR (400 MHz, CDCl3-d3) δ 15.49 (br s, 1H), 7.33-7.45 (m, 5H), 5.53 (s, 1H), 3.66 (s, 2H), 2.10 (s, 3H).

Workup

  1. additionAfter addition
  2. customThe organic layer was separated
  3. concentrationconcentrated in vacuo
  4. customThe crude product was purified by silica gel chromatography

Sources & evidence

ORD record
ord-6571affbab814b0c990e09d15313c265
Source dataset
uspto-grants-2015_03
Patent number
US08975291B2

Reaction notes

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