Acetic Acid → 2-Phenylacetophenone

HRID 1905822Notes

Reaction equation

HRID 1905822 reaction equation
[C:1]1([C:7]([CH:9]([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)O)=[O:8])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C1(P(Cl)C2C=CC=CC=2)C=CC=CC=1.[Li].C(O)(=O)C.CI>C1COCC1.O>[C:1]1([C:7]([CH2:9][C:11]2[CH:12]=[CH:13][CH:14]=[CH:15][CH:16]=2)=[O:8])[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

8

Reactant 5

HCID 176Acetic AcidHCID 6328Methyl iodideHCID 8400Benzoin2×HCID 66180ChlorodiphenylphosphineHCID 3028194Lithium2×

Product 1

HCID 99482-Phenylacetophenone

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

Dehydroxylation of Benzoin. Diphenylphosphinouschloride (5.0 g, 22.6 mmol) was added dropwise to a suspension of lithium shot (158 mg, 22.6 mmol) in THF (10 ml) at room temperature. After about 2 hours all the lithium had dissolved and a solution of benzoin (2.4 g, 11.3 mmol) in THF (25 ml) was added dropwise. The clear yellow reaction mixture was stirred overnight at room temperature and turned a bright orange color. Acetic acid (678 mg, 11.2 mmol) was then added, followed by methyliodide (1.6 g, 11.3 mmol). After stirring for an additional 30 minutes, the reaction mixture was poured into water (100 ml) and extracted with ethyl acetate. The combined organic extracts were dried over magnesium sulfate and concentrated in vacuo giving a yellow oil. MPLC purification on silica gel (eluting solvent, ethyl acetate) gave desoxybenzoin (1.7 g, 76 wt % yield) as a white crystalline solid.

Workup

  1. customat room temperature
  2. stirringAfter stirring for an additional 30 minutes
  3. extractionextracted with ethyl acetate
  4. dry with materialThe combined organic extracts were dried over magnesium sulfate
  5. concentrationconcentrated in vacuo
  6. customgiving a yellow oil
  7. customMPLC purification on silica gel (eluting solvent, ethyl acetate)

Sources & evidence

ORD record
ord-697bb536e976471fb228480601ca443e
Source dataset
uspto-grants-1987_03
Patent number
US04647702

Reaction notes

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