Reaktion #938458

Reaktionsgleichung

water

ammonia

butyl 2,6-difluoropyridine-3-carboxylate

→

butyl 2-amino-6-fluoropyridine-3-carboxylate

Ausbeute 34.9%

Lösungsmittel

formamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Filtrationthe product was filtered
2. 2
   WaschenAfter washing with several portions of water
3. 3
   workup.DISSOLUTIONthe solid was dissolved in chloroform
4. 4
   Trocknendried (MgSO4)
5. 5
   Sonstigethe solvent evaporated
6. 6
   SonstigeThe resulting solid (26 g, m.p.=84°-120° C.) was separated via preparative high pressure liquid chromatography (8:2 hexane-acetone)

Vorschrift

To a mechanically stirred solution of ammonia (14 grams (g)) in formamide (300 milliliter (ml)) was added all at once butyl 2,6-difluoropyridine-3-carboxylate (29 g, 0.135 mole). The resulting mixture was stirred overnight at room temperature. The mixture was then poured into water (1500 ml) and the product was filtered. After washing with several portions of water, the solid was dissolved in chloroform, dried (MgSO4) and the solvent evaporated. The resulting solid (26 g, m.p.=84°-120° C.) was separated via preparative high pressure liquid chromatography (8:2 hexane-acetone) to give first the desired butyl 2-amino-6-fluoropyridine-3-carboxylate (10 g) which after recrystallization from hexane had a m.p.=88.5°-90.5° C. Eluting second was the isomeric butyl 6-amino-2-fluoropyridine-3-carboxylate (9 g) which after recrystallization from toluene had a m.p.=132.5°-134° C.

Quelle