Reaktion #46130

Reaktionsgleichung

2-amino-5-methoxybenzenesulphonamide

(1-ethoxycyclopropyloxy)trimethylsilane

acetic acid

→

expected compound

2-cyclopropylamino-5-methoxybenzenesulphonamide

Lösungsmittel

methanol

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturheating
2. 2
   Temperaturat reflux
3. 3
   SonstigeThe mixture is then evaporated to dryness under reduced pressure
4. 4
   SonstigeThe oil obtained
5. 5
   Extraktionextracted with chloroform (3×30 mL)
6. 6
   SonstigeThe organic phases are collected
7. 7
   Trocknendried over anhydrous MgSO4
8. 8
   FiltrationAfter filtration
9. 9
   Sonstigethe filtrate is evaporated to dryness
10. 10
    workup.DISSOLUTIONthe residual oil is dissolved in THF (50 mL)
11. 11
    workup.ADDITIONSodium borohydride (2 g) and boron trifluoride etherate (2 mL) are added
12. 12
    Temperaturthe mixture is heated
13. 13
    Temperaturat reflux for 18 hours
14. 14
    SonstigeThe solvent is then removed by evaporation under reduced pressure
15. 15
    workup.ADDITIONby adding 6N HCl
16. 16
    Extraktionextracted with chloroform (3×30 mL)
17. 17
    SonstigeThe organic phases are collected
18. 18
    Trocknendried over anhydrous MgSO4
19. 19
    FiltrationAfter filtration
20. 20
    Sonstigethe filtrate is evaporated to dryness

Vorschrift

To a solution of 2-amino-5-methoxybenzenesulphonamide (4.9 mmol) in methanol (20 mL) there are added (1-ethoxycyclopropyloxy)trimethylsilane (4 mL) and glacial acetic acid (4 mL) and then heating at reflux is carried out for 18 hours. The mixture is then evaporated to dryness under reduced pressure. The oil obtained is taken up in water (30 mL) and extracted with chloroform (3×30 mL). The organic phases are collected and dried over anhydrous MgSO4. After filtration, the filtrate is evaporated to dryness and the residual oil is dissolved in THF (50 mL). Sodium borohydride (2 g) and boron trifluoride etherate (2 mL) are added and then the mixture is heated at reflux for 18 hours. The solvent is then removed by evaporation under reduced pressure and the residue is taken up in water (30 mL), adjusted to slightly acid pH by adding 6N HCl and then extracted with chloroform (3×30 mL). The organic phases are collected and dried over anhydrous MgSO4. After filtration, the filtrate is evaporated to dryness and the expected compound is obtained in the form of an oil used directly in the next Step.

Quelle