Hydrochloric Acid → Dihydro-8-fluoro-2H-1,4-benzoxazine-2-methanamine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of 4b (0.75 g, 3.83 mmol) in anhydrous THF (20 mL) held at ambient temperature in an inert atmosphere, is added dropwise a solution of LiAlH4 in THF (13.4 mL, 13.4 mmol). When addition is completed, the mixture is heated to 60° C. for 11 h. The mixture obtained is cooled to 0° C. then an aqueous solution of hydrochloric acid (1N) is added slowly until a pH of 3 is reached. The mixture is concentrated under reduced pressure then the residue is made alkaline through the addition of an aqueous NaOH solution (1N). The mixture is extracted with ethyl acetate, the organic phase is washed with water then with salt water, dried over MgSO4 and concentrated under reduced pressure. The residue is purified by silica gel chromatography using a dichloromethane-methanol mixture (85:5) as eluting solvent. The title compound is obtained in oil form (1.1 g, 59%).

Herkunft & Nachweise