Reaktion #65929

Reaktionsgleichung

3-Dipropylamino-5-methyloxycarbonylchroman

Sodium hydroxide

diphenylphosphoryl azid

→

title compound

3-Dipropylamino-5-aminochroman

Lösungsmittel

Methanol

methanol

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe solution was refluxed with nitrogen overnight
2. 2
   SonstigeThe solution was evaporated to dryness, toluene (20 ml)
3. 3
   workup.ADDITIONwas added
4. 4
   Sonstigeagain the solution was evaporated to dryness
5. 5
   workup.DISSOLUTIONThe residue was dissolved in toluene 20 ml
6. 6
   Temperaturthe solution was refluxed for 2 hours
7. 7
   Temperaturreflux
8. 8
   TemperaturThe solution was cooled
9. 9
   Waschenwashed with water
10. 10
    Extraktionextracted with dilute HCl (aq.)
11. 11
    Extraktionextracted with toluene
12. 12
    TrocknenThe toluene-phase was dried with sodium sulphate
13. 13
    Sonstigeevaporated to dryness
14. 14
    workup.DISSOLUTIONThe residue was dissolved in ethanol containing 10% NaOH (20 ml)
15. 15
    Temperaturthe solution was refluxed overnight
16. 16
    TemperaturThe solution was cooled
17. 17
    workup.ADDITIONdiluted with toluene
18. 18
    WaschenWashing with water
19. 19
    Sonstigedrying of the organic phase and evaporation to dryness

Vorschrift

3-Dipropylamino-5-methyloxycarbonylchroman (Example 2; 1.0 g, 3.4 mmol) was dissolved in methanol (20 ml). Sodium hydroxide (0.16 g, 4.1 mmol) in water (1.0 ml) was added and the solution was refluxed with nitrogen overnight. The solution was evaporated to dryness, toluene (20 ml) was added and again the solution was evaporated to dryness. The residue was dissolved in toluene 20 ml, diphenylphosphoryl azid (1.87 g, 6.8 mmol) was added and the solution was refluxed for 2 hours. Methanol (2.0 ml) was added and reflux was continued for 4 hours. The solution was cooled, washed with water and extracted with dilute HCl (aq.). The acidic water phase was neutralized NaOH (aq.) and extracted with toluene. The toluene-phase was dried with sodium sulphate and evaporated to dryness. The residue was dissolved in ethanol containing 10% NaOH (20 ml) and the solution was refluxed overnight. The solution was cooled and diluted with toluene. Washing with water, drying of the organic phase and evaporation to dryness afforded the title compound as an oil, which was converted to a dihydrochloride salt. Mp 173°-174° C.

Quelle