Imidazole → (E)-3-[2(tert-Butyl-dimethyl-silanoxy)-phenyl]-acrylic acid

HRID 1870584Notes

Reaction equation

HRID 1870584 reaction equation
[OH:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1/[CH:8]=[CH:9]/[C:10]([OH:12])=[O:11].[CH3:13][C:14]([Si:17](Cl)([CH3:19])[CH3:18])([CH3:16])[CH3:15].N1C=CN=C1.[Li+].[OH-]>CN(C=O)C.C1COCC1.O>[C:14]([Si:17]([CH3:19])([CH3:18])[O:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1/[CH:8]=[CH:9]/[C:10]([OH:12])=[O:11])([CH3:16])([CH3:15])[CH3:13]

Participants

7

Reactant 4

HCID 795ImidazoleHCID 3939Lithium HydroxideHCID 28928tert-Butyldimethylsilyl chlorideHCID 637540O-Coumaric Acid

Product 1

HCID 22290462(E)-3-[2(tert-Butyl-dimethyl-silanoxy)-phenyl]-acrylic acidYield 53.9%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 21881883Oxolane--water (1/1)Solvent

Procedure

To a solution of 8.2 g of (E)-3-(2-hydroxy-phenyl)-acrylic acid and 15.2 g of TBDMS-Cl in 10 ml of DMF was added 11.9 g of imidazole and the mixture was stirred at room temperature for 24 h. After aqueous work-up, the bis-silylated product was saponified with 2.1 g of LiOH in THF-H2O for 0.5 h at 0° C. The mixture was concentrated in vacuo and TBDMS-OH removed by extraction with hexane. The aqueous layer was acidified to pH 4 with KHSO4 and extracted with EtOAc. The organic phases were washed with brine, dried (Na2SO4) and evaporated to dryness. The semi-solid residue was suspended in hexane, filtered and the filtrate evaporated to dryness to yield 7.5 g of a pale yellow oil, which solidified upon standing.

Workup

  1. concentrationThe mixture was concentrated in vacuo and TBDMS-OH
  2. customremoved by extraction with hexane
  3. extractionextracted with EtOAc
  4. washThe organic phases were washed with brine
  5. dry with materialdried (Na2SO4)
  6. customevaporated to dryness
  7. filtrationfiltered
  8. customthe filtrate evaporated to dryness

Sources & evidence

ORD record
ord-6705daeb889843aa95a7d9ee77323cb2
Source dataset
uspto-grants-2000_08
Patent number
US06096918

Reaction notes

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