Reaktion #165244

ord-b8f4346876a346f1a158cb653600e3d9

Lösungsmittel

Reaktionsbedingungen

Temperatur
-78°CELSIUS
Detaillierte Bedingungen
See reaction.notes.procedure_details.

Aufarbeitung

  1. 1
    workup.ADDITIONwas then added dropwise
  2. 2
    workup.STIRRINGstirred for 10 minutes at −78° C
  3. 3
    Sonstigewas allowed to room temperature
  4. 4
    Extraktionfollowed by extraction with ethyl acetate
  5. 5
    WaschenThe organic layer was washed with saturated aqueous sodium chloride
  6. 6
    Sonstigethe solvent was evaporated under a reduced pressure
  7. 7
    SonstigeThe residue was purified by NH silica gel column chromatography (ethyl acetate:heptane=1:5→1:1)

Vorschrift

To an anhydrous tetrahydrofuran (70.0 mL) solution of 2,5-dibromothiophene (5.00 g, 19.6 mmol) was added dropwise n-butyl lithium (2.55 M n-hexane solution, 7.69 mL, 19.6 mmol) on a dry ice-ethanol bath (−78° C.) under nitrogen atmosphere, which was stirred for 20 minutes at −78° C. p-Tolaldehyde (2.35 g, 19.6 mmol) was then added dropwise and stirred for 10 minutes at −78° C. The reaction mixture was allowed to room temperature and water was added, followed by extraction with ethyl acetate. The organic layer was washed with saturated aqueous sodium chloride, and the solvent was evaporated under a reduced pressure. The residue was purified by NH silica gel column chromatography (ethyl acetate:heptane=1:5→1:1) to obtain the title compound (4.30 g, 77.5%).

Quelle

DOI: 10.6084/m9.figshare.5104873.v1Patent: US08841327B2uspto-grants-2014_09