Acetic Anhydride → 4-Benzyloxyphenylacetone

HRID 2368954Notes

Reaction equation

HRID 2368954 reaction equation
[CH2:1]([O:8][C:9]1[CH:14]=[CH:13][C:12]([CH2:15][C:16]([OH:18])=O)=[CH:11][CH:10]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[C:19](OC(=O)C)(=O)C>N1C=CC=CC=1>[CH2:1]([O:8][C:9]1[CH:10]=[CH:11][C:12]([CH2:15][C:16](=[O:18])[CH3:19])=[CH:13][CH:14]=1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 810334-Benzyloxyphenylacetic acid

Product 1

HCID 5612534-Benzyloxyphenylacetone

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

To 10.0 g (41.3 mmol) of 4-benzyloxyphenylacetic acid (31) was added, 20 mL of acetic anhydride and 20 mL of pyridine, which was heated to reflux with stirring under argon atmosphere for 6 hours. Solvents were evaporated and residue dissolved in CHCl3 (50 mL) and washed with 1N NaOH (2×50 mL). Dried organic layer (MgSO4), filtered, and evaporated to 11.8 g of an amber oil. Vacuum distillation at 0.1 mm Hg in an oil-bath set to 170° C. followed by silica gel chromatography eluting with 8/2 CH2Cl2-hexanes gave 2.68 g (27%). 1H NMR (CDCl3) □δ□ 2.14 (s, 3H), 3.63 (s, 2H), 5.05 (s, 2H), 6.94 (d, 2H, J=8.7 Hz), 7.10 (d, 2H, J=8.7 Hz), 7.26-7.47 (m, 5H).

Workup

  1. temperatureto reflux
  2. customSolvents were evaporated
  3. dissolutionresidue dissolved in CHCl3 (50 mL)
  4. washwashed with 1N NaOH (2×50 mL)
  5. filtrationDried organic layer (MgSO4), filtered
  6. customevaporated to 11.8 g of an amber oil
  7. distillationVacuum distillation at 0.1 mm Hg in an oil-bath
  8. customset to 170° C.
  9. washeluting with 8/2 CH2Cl2-hexanes
  10. customgave 2.68 g (27%)

Sources & evidence

ORD record
ord-6f6c539a55ce4da1a0564c2441f342cd
Source dataset
uspto-grants-2014_04
Patent number
US08703826B2

Reaction notes

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