Reacción #172396

ord-69c786a9737c47cc97242a66e059c0b4

Condiciones de reacción

Temperatura
5°CELSIUS
Condiciones detalladas
See reaction.notes.procedure_details.

Tratamiento posterior

  1. 1
    TemperaturaCooling
  2. 2
    Otrois removed
  3. 3
    TemperaturaThe mixture is then again cooled to 5° C.
  4. 4
    workup.ADDITION400 ml of 1N aqueous sodium hydroxide solution are added
  5. 5
    workup.ADDITIONAfter the addition
  6. 6
    workup.ADDITION81 ml of 30% strength hydrogen peroxide solution are added a little at a time at this temperature
  7. 7
    LavadoAfter dilution with 500 ml of ethyl acetate, the mixture is washed with 32 ml of 40% strength sodium bisulphite solution
  8. 8
    Otroto destroy the peroxides
  9. 9
    OtroThe organic phase is separated off
  10. 10
    Extracciónthe aqueous phase is extracted four times with ethyl acetate
  11. 11
    LavadoThe combined organic phases are washed with saturated sodium chloride solution
  12. 12
    Secadodried over magnesium sulphate
  13. 13
    Filtraciónafter filtration
  14. 14
    Concentraciónconcentrated to dryness under reduced pressure
  15. 15
    OtroThe residue is chromatographed on silica gel using a gradient of cyclohexane and ethyl acetate
  16. 16
    Concentraciónconcentrated to dryness under reduced pressure

Procedimiento

23 g (80 mmol) of the compound from Example 29A are dissolved in 80 ml of anhydrous tetrahydrofuran and cooled to 5° C. Over a period of 15 min, 21 g (176 mmol) of 9-borabicyclo[3.3.1]nonane (0.5M solution in tetrahydrofuran) are added. Cooling is removed, and the mixture is stirred at room temperature for another 2 h. The mixture is then again cooled to 5° C., and 400 ml of 1N aqueous sodium hydroxide solution are added. After the addition has ended, 81 ml of 30% strength hydrogen peroxide solution are added a little at a time at this temperature. After dilution with 500 ml of ethyl acetate, the mixture is washed with 32 ml of 40% strength sodium bisulphite solution to destroy the peroxides. The organic phase is separated off, and the aqueous phase is extracted four times with ethyl acetate. The combined organic phases are washed with saturated sodium chloride solution, dried over magnesium sulphate and, after filtration, concentrated to dryness under reduced pressure. The residue is chromatographed on silica gel using a gradient of cyclohexane and ethyl acetate. The product-containing fractions are combined and concentrated to dryness under reduced pressure. This gives 20 g (77% of theory) of the desired product.

Fuente

DOI: 10.6084/m9.figshare.5104873.v1Patente: US08846934B2uspto-grants-2014_09