Reaktion #59861

Reaktionsgleichung

4-(2-(8-ethyl-1,4,7,9-tetraoxaspiro[4.5]dec-8-yl)ethoxy)-2,3-dimethylpyridine 1-oxide

triethylamine

acetic anhydride

→

title compound

Ausbeute 59.6%

(4-(2-(8-ethyl-1,4,7,9-tetraoxaspiro[4.5]dec-8-yl)ethoxy)-3-methylpyridin-2-yl)methanol

Ausbeute 59.6%

Reaktionsbedingungen

Aufarbeitung

1. 1
   EinengenThe reaction mixture was concentrated
2. 2
   workup.ADDITIONmethanol (10 ml) was added to the residue
3. 3
   workup.ADDITIONa 5N aqueous sodium hydroxide solution (7 ml) was added
4. 4
   workup.STIRRINGstirred at room temperature for one hour
5. 5
   workup.ADDITIONTo the mixture, a saturated aqueous ammonium chloride solution (7 ml) was added
6. 6
   workup.ADDITIONThe reaction mixture was diluted with ethyl acetate
7. 7
   Waschenthe organic layer was washed with a 2N aqueous sodium hydroxide solution, water
8. 8
   Trocknena saline solution, dried over anhydrous sodium sulfate
9. 9
   Einengenconcentrated
10. 10
    SonstigeThe obtained crude product
11. 11
    Sonstigewas purified by silica gel column chromatography (elution solvent: ethyl acetate/methanol=1/0-4/1 gradient)
12. 12
    Einengena desired fraction(s) was concentrated

Vorschrift

The 4-(2-(8-ethyl-1,4,7,9-tetraoxaspiro[4.5]dec-8-yl)ethoxy)-2,3-dimethylpyridine 1-oxide (947 mg, 2.79 mmol) obtained in the step (4f) was mixed with acetic anhydride (10 ml). To the mixture, triethylamine (0.6 ml, 4.3 mmol) was added and stirred at 50° C. for 2 hours. The reaction mixture was concentrated and methanol (10 ml) was added to the residue and thereafter, a 5N aqueous sodium hydroxide solution (7 ml) was added and stirred at room temperature for one hour. To the mixture, a saturated aqueous ammonium chloride solution (7 ml) was added and the pH of the resultant solution 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 (564 mg, yield: 59.6%) as a light yellow solid.

Quelle