Réaction #5817

ord-16583531d898465db747873666a6aa4e

Conditions de réaction

Conditions détaillées
See reaction.notes.procedure_details.

Traitement

  1. 1
    workup.ADDITIONwas added to the reaction mixture, which
  2. 2
    Extractionwas then extracted twice with 20 ml of chloroform
  3. 3
    Séchagethe extract was dried over magnesium sulfate
  4. 4
    Concentrationconcentrated under a reduced pressure
  5. 5
    Autreto obtain a residue
  6. 6
    Températurethe mixture was refluxed for two hours
  7. 7
    Séchagedried over magnesium sulfate
  8. 8
    Concentrationconcentrated under a reduced pressure
  9. 9
    Lavageeluted with chloroform/methanol (80:1 to 50:1)

Mode opératoire

620 mg of the crude product obtained in Example 28 was dissolved in 10 ml of methylene chloride, and to the solution were sequentially added 0.29 ml of benzyloxycarbonyl chloride and 3.04 ml of triethylamine with ice cooling. After stirring for two hours with ice cooling, 40 ml of saturated sodium chloride aqueous solution was added to the reaction mixture, which was then extracted twice with 20 ml of chloroform, and the extract was dried over magnesium sulfate and concentrated under a reduced pressure to obtain a residue. The residue was dissolved in 6 ml of methanol, and after the addition of 2 ml of 1N sodium hydroxide aqueous solution, the mixture was refluxed for two hours, dried over magnesium sulfate and concentrated under a reduced pressure. The resulting residue was applied to a silica gel column and eluted with chloroform/methanol (80:1 to 50:1) to obtain 336 mg of the title compound as colorless crystals.

Source

DOI: 10.6084/m9.figshare.5104873.v1Brevet: US05245034uspto-grants-1993_09