反应详情

A solution of 50 g (0.66 mol) of ammonium acetate in 200 ml of methanol, 2.7 g (0.43 mol) of sodium cyanoborohydride and about 100 mg of 4-tert-butylpyrocatechol are added to a solution of 20 g (0.066 mol) of 4-(2-bromoethyl)-phenyl benzyl ketone in 100 ml of dioxane. After the mixture has been stirred for 48 hours at room temperature, it is acidified with 50 ml of concentrated hydrochloric acid (pH 2). Thereafter, methanol and dioxane are substantially distilled off under about 2 kPa and are replaced by ethyl acetate. The solution is washed with twice 100 ml of water and evaporated down under about 2 kPa. The residue is taken up with ethanol/diethyl ether (1:1). The white precipitate formed is filtered off, and the filtrate is evaporated down to give an oil. After the addition of 50 ml of ethyl acetate, the product begins to crystallize. It is filtered off under suction and dried. Yield: 10.8 g (48% of theory) of white crystals. Melting point: 165°-168° C./decomposition.

1. distillationThereafter, methanol and dioxane are substantially distilled off under about 2 kPa
2. washThe solution is washed with twice 100 ml of water
3. customevaporated down under about 2 kPa
4. customThe white precipitate formed
5. filtrationis filtered off
6. customthe filtrate is evaporated down
7. customto give an oil
8. customto crystallize
9. filtrationIt is filtered off under suction
10. customdried