Reaction #742259

Reaction equation

(E)-3-(2-hydroxy-phenyl)-acrylic acid

TBDMS-Cl

imidazole

LiOH

→

pale yellow oil

Yield 53.9%

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

Yield 53.9%

Solvents

DMF

THF H2O

Conditions

Workup

1. 1
   ConcentrationThe mixture was concentrated in vacuo and TBDMS-OH
2. 2
   Otherremoved by extraction with hexane
3. 3
   Extractionextracted with EtOAc
4. 4
   WashThe organic phases were washed with brine
5. 5
   Dryingdried (Na2SO4)
6. 6
   Otherevaporated to dryness
7. 7
   Filtrationfiltered
8. 8
   Otherthe filtrate evaporated to dryness

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.

Source