Reacción #59867

ord-b4e613da362d4a50a73b0d94348033e9

Condiciones de reacción

Temperatura
50°CELSIUS
Condiciones detalladas
See reaction.notes.procedure_details.

Tratamiento posterior

  1. 1
    ConcentraciónThe reaction mixture was concentrated
  2. 2
    workup.ADDITIONmethanol (10 ml) was added to the residue
  3. 3
    workup.ADDITIONThereafter a 5N aqueous sodium hydroxide solution (7 ml) was added to the mixture
  4. 4
    workup.STIRRINGstirred at room temperature for 30 minutes
  5. 5
    workup.ADDITIONTo the resultant mixture, a saturated aqueous ammonium chloride solution (7 ml) was added
  6. 6
    workup.ADDITIONThe reaction mixture was diluted with ethyl acetate
  7. 7
    Lavadothe organic layer was washed with a 2N aqueous sodium hydroxide solution, water
  8. 8
    Secadoa saline solution, dried over anhydrous sodium sulfate
  9. 9
    Concentraciónconcentrated
  10. 10
    OtroThe obtained crude product
  11. 11
    Otrowas purified by silica gel column chromatography (elution solvent: ethyl acetate/methanol=1/0-4/1 gradient)
  12. 12
    Concentracióna desired fraction(s) was concentrated

Procedimiento

The 2,3-dimethyl-4-((8-methyl-1,4,7,9-tetraoxaspiro[4.5]dec-8-yl)methoxy)pyridine 1-oxide (1.20 g, 3.84 mmol) obtained in the step (5d) was mixed with acetic anhydride (10 ml). To the mixture, triethylamine (0.8 ml, 5.74 mmol) was added and the mixture was stirred at 50° C. for 2 hours. The reaction mixture was concentrated and methanol (10 ml) was added to the residue. Thereafter a 5N aqueous sodium hydroxide solution (7 ml) was added to the mixture, and stirred at room temperature for 30 minutes. To the resultant mixture, a saturated aqueous ammonium chloride solution (7 ml) was added and the pH was adjusted to about 10. The reaction mixture was diluted with ethyl acetate, and the organic layer was washed with a 2N aqueous sodium hydroxide solution, water, and a saline solution, dried over anhydrous sodium sulfate and concentrated. The obtained crude product was purified by silica gel column chromatography (elution solvent: ethyl acetate/methanol=1/0-4/1 gradient) and a desired fraction(s) was concentrated to obtain the title compound (312 mg, 26.1% yield) as a light yellow solid.

Fuente

DOI: 10.6084/m9.figshare.5104873.v1Patente: US07425634B2uspto-grants-2008_09