Reaktion #43733

Reaktionsgleichung

N-[(3R)-1-azabicyclo[2.2.2]oct-3-yl]-7-methoxy-5-nitro-1-benzofuran-2-carboxamide hydrochloride

sodium hydroxide

ammonium formate

→

title compound

5-Amino-N-[(3R)-1-azabicyclo[2.2.2]oct-3-yl]-7-methoxy-1-benzofuran-2-carboxamide dihydrochloride

Lösungsmittel

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   ExtraktionThe aqueous phase is extracted repeatedly with ethyl acetate
2. 2
   TrocknenThe extract is dried over magnesium sulfate
3. 3
   Sonstigethe solvent is removed under reduced pressure
4. 4
   workup.DISSOLUTIONThe free base is dissolved in 3 ml of methanol
5. 5
   Temperaturthe mixture is heated
6. 6
   Temperaturunder reflux for 4 h
7. 7
   FiltrationThe reaction mixture is filtered through Celite
8. 8
   Waschenthe filter cake is washed with ethanol and ethyl acetate
9. 9
   SonstigeThe crude product is subjected to fine purification on silica gel 60 (mobile phase: dichloromethane→dichloromethane/methanol 10:1→dichloromethane/methanol/ammonia 80:20:2)
10. 10
    workup.ADDITIONAn excess of 4N HCl in dioxane is added to the free base
11. 11
    SonstigeThe solvent is then removed under reduced pressure

Vorschrift

Initially, N-[(3R)-1-azabicyclo[2.2.2]oct-3-yl]-7-methoxy-5-nitro-1-benzofuran-2-carboxamide hydrochloride (120 mg, 0.31 mmol) is converted into the free base. To this end, the compound is taken up in ethyl acetate, and 30% strength aqueous sodium hydroxide solution is added. The aqueous phase is extracted repeatedly with ethyl acetate. The extract is dried over magnesium sulfate and the solvent is removed under reduced pressure. The free base is dissolved in 3 ml of methanol. 120 mg (1.84 mmol) of ammonium formate are added, and the mixture is heated under reflux for 4 h. The reaction mixture is filtered through Celite, and the filter cake is washed with ethanol and ethyl acetate. The crude product is subjected to fine purification on silica gel 60 (mobile phase: dichloromethane→dichloromethane/methanol 10:1→dichloromethane/methanol/ammonia 80:20:2). An excess of 4N HCl in dioxane is added to the free base. The solvent is then removed under reduced pressure. 25 mg (17% of theory) of the title compound are isolated.

Quelle