Methanol → Methyl 2,4-bis-benzyloxy-5-isopropenylbenzoate

HRID 2355676Notes

Reaction equation

HRID 2355676 reaction equation
[CH2:1]([Li])[CH2:2][CH2:3][CH3:4].[C:6]([C:9]1[C:10]([O:27][CH2:28][C:29]2[CH:34]=[CH:33][CH:32]=[CH:31][CH:30]=2)=[CH:11][C:12]([O:19]CC2C=CC=CC=2)=[C:13]([CH:18]=1)[C:14]([O:16][CH3:17])=[O:15])(=O)[CH3:7].[CH3:35]O.O1C[CH2:40][CH2:39][CH2:38]1>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>[CH2:1]([O:19][C:12]1[CH:11]=[C:10]([O:27][CH2:28][C:29]2[CH:34]=[CH:33][CH:32]=[CH:31][CH:30]=2)[C:9]([C:6]([CH3:35])=[CH2:7])=[CH:18][C:13]=1[C:14]([O:16][CH3:17])=[O:15])[C:2]1[CH:40]=[CH:39][CH:38]=[CH:4][CH:3]=1

Participants

6

Reactant 4

HCID 887MethanolHCID 8028Tetrahydrofuran2×HCID 11955869Methyl 5-acetyl-2,4-bis-benzyloxybenzoateHCID 178418339Butyllithium

Product 1

HCID 11955870Methyl 2,4-bis-benzyloxy-5-isopropenylbenzoateYield 36%

Reagents, catalysts & solvents 1

HCID 74505Methyltriphenyliphosphonium bromideCatalyst

Conditions

Temperature
0 °C

Procedure

A stirred suspension of methyltriphenylphosphonium bromide (1.96 g, 5.5 mmol) in anhydrous tetrahydrofuran (20 ml) at 0° C. under a nitrogen atmosphere was treated dropwise with n-butyl lithium (1.6 M in hexanes, 3.5 ml, 5.5 mmol) and the resulting bright yellow solution was stirred at 0° C. for 30 minutes. A solution of methyl 5-acetyl-2,4-bis-benzyloxybenzoate (1.95 g, 5.00 mmol) in anhydrous tetrahydrofuran (20 ml) was added dropwise and the resulting mixture was allowed to warm to room temperature and was stirred for 16 hours. Methanol (10 ml) was added and the solvent was removed in vacuo. The residues were partitioned between dichloromethane and water, the organic layer was separated and the solvent removed in vacuo to afford a brown gum that was purified by column chromatography on silica. Elution with 7% ethyl acetate in petroleum ether afforded methyl 2,4-bis-benzyloxy-5-isopropenyl-benzoate as a colourless solid (700 mg, 36%). 1H NMR (DMSO-d6) 7.59 (1H, s), 7.52 (2H, d), 7.64-7.32 (8H, m), 6.97 (1H, s), 5.28 (2H, s), 5.22 (2H, s), 5.09 (1H, s), 5.04 (1H, s), 3.76 (3H, s), 2.02 (3H, s). MS: [M+H]+ 389.

Workup

  1. temperatureto warm to room temperature
  2. stirringwas stirred for 16 hours
  3. customthe solvent was removed in vacuo
  4. customThe residues were partitioned between dichloromethane and water
  5. customthe organic layer was separated
  6. customthe solvent removed in vacuo
  7. customto afford a brown gum that
  8. customwas purified by column chromatography on silica
  9. washElution with 7% ethyl acetate in petroleum ether

Sources & evidence

ORD record
ord-b03362c98b574c8894fc8867f69080f7
Source dataset
uspto-grants-2010_07
Patent number
US07754725B2

Reaction notes

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