2-氨基-2-(4-溴-3-氟苯基)乙烷-1-醇

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a stirred, cooled (0° C.) solution of (RS)-2-amino-2-(4-bromo-3-fluoro-phenyl)-ethanol (3.26 g) and sodium acetate (2.22 g) in methanol (25 ml) was added dropwise a solution of cyanogen bromide (1.52 g) in methanol (10 ml) over 10 min. The mixture was then allowed to warm to at r.t. and stirring continued for 16 h. The mixture was concentrated in vacuo and the residue was resuspended in water and made basic by addition of 1 M aq sodium hydroxide solution. The mixture was then extracted twice with dichloromethane and the combined organic phases were dried over sodium sulphate and concentrated in vacuo. The residue was triturated in dichloromethane and the resultign crystals washed with ether to give (RS)-4-(4-bromo-3-fluoro-phenyl)-4,5-dihydro-oxazol-2-ylamine (1.09 g, 30%) as a white solid. MS (ISP): 261.0 ([{81Br}M+H]+), 258.9 ([{79Br}M+H]+). The mixture was concentrated in vacuo made basic by addition of 1 M aq sodium hydroxide solution The mixture was then extracted twice with dichloromethane the combined organic phases were dried over sodium sulphate concentrated in vacuo The residue was triturated in dichloromethane the resultign crystals washed with ether