Réaction #64628

ord-9d47cd5a2df5456e8ccd5693296c6f61

Conditions de réaction

Conditions détaillées
See reaction.notes.procedure_details.

Traitement

  1. 1
    Températurewas heated
  2. 2
    Températureat reflux for 1.5 hour
  3. 3
    AutreThe excess thionyl chloride was removed under reduced pressure
  4. 4
    Températurethe mixture was cooled in an ice-bath
  5. 5
    Autrequenched by the addition of 50 ml of an ice/water mixture
  6. 6
    AutreThe organic layer was separated
  7. 7
    Extractionthe aqueous layer extracted with 2×50 ml of ether
  8. 8
    Lavagewashed successively with water and saturated NaCl solution
  9. 9
    Séchagedried (MgSO4)
  10. 10
    AutreThe solvent was then removed in-vacuo
  11. 11
    workup.DISTILLATIONthe residue purified by distillation (~80 degrees C./0.01 mm)

Mode opératoire

A mixture of 25 g (0.215 mol) of 4-methyl valeric acid and 29.35 g (0.247 mol) of thionyl chloride was heated at reflux for 1.5 hour. The excess thionyl chloride was removed under reduced pressure using a cryogenic trap. The residue was taken up with 120 g (0.764 mol) of bromobenzene (Compound 27) and the mixture was cooled in an ice-bath and then treated with 23 g (0.172 mol) of anhydrous aluminum chloride through a powder addition funnel. The mixture was stirred at room temperature for 82 h and then quenched by the addition of 50 ml of an ice/water mixture, followed by 30 ml of conc. HCl. The organic layer was separated and the aqueous layer extracted with 2×50 ml of ether. The organic extracts were combined and washed successively with water and saturated NaCl solution and then dried (MgSO4). The solvent was then removed in-vacuo and the residue purified by distillation (~80 degrees C./0.01 mm) to give the title compound as a colorless solid. PMR (CDCl3): & 0.94 (6H, d, J~6.0 Hz), 1.53-1.68 (3H, m), 2.85-2.97 (2H, m)., 7.60 (2H, d, J~8.4 Hz), 7.83 (2H, d, J~8.4 Hz).

Source

DOI: 10.6084/m9.figshare.5104873.v1Brevet: US05414007uspto-grants-1995_05