反应详情

温度

-20 °C

To a solution of 2.75 gm (0.01 mol) of 4-(4'-fluoro-4-biphenylyl)-4-oxo-butyric acid in 50 ml of absolute tetrahydrofuran 0.20 gm (0.005 mol) of lithiumaluminumhydride in 50 ml of absolute tetrahydrofuran was added dropwide, while stirring and cooling at -20° C. After stirring for 4 hours at -20° C., the reaction mixture was poured into ice water and acidified with aqueous 50% sulfuric acid. Subsequently, the mixture was made alkaline by adding aqueous 20% sodium hydroxide, and was again acidified with formic acid. The precipitated semi-solid product was dissolved in ether, and after evaporating the ether, the crystalline residue was dissolved in acetone. From this solution the cyclohexylamine salt of 4-(4'-fluoro-4-biphenylyl)-4-hydroxy-butyric acid was precipitated by addition of cyclohexylamine, and the salt was recrystallized from ethyl acetate/absolute ethanol. Melting point 176°-178° C. (decomp.); yield: 2.2 gm.

1. stirringAfter stirring for 4 hours at -20° C.
2. customafter evaporating the ether
3. dissolutionthe crystalline residue was dissolved in acetone
4. customFrom this solution the cyclohexylamine salt of 4-(4'-fluoro-4-biphenylyl)-4-hydroxy-butyric acid was precipitated by addition of cyclohexylamine
5. customthe salt was recrystallized from ethyl acetate/absolute ethanol