求教三乙酰氧基硼氢化钠的制备方法，谢谢
求教三乙酰氧基硼氢化钠的制备方法，谢谢[[i] 本帖最后由 mating 于 2008-6-11 21:30 编辑 [/i]] 可以用二氯乙烷或二氯甲烷作溶济,先加入硼氢化钠,10度以下滴加3当量的醋酸,室温下搅拌过夜即可.注意用机械搅拌. 谢谢楼上的 搅拌过夜之后是不是旋干溶剂二氯甲烷就的到三乙酰氧硼氢化钠的固体就可以了呀 A 100 Schlenk flask equipped with a Schlenk filter was charged with 186 mg (4.93 mmol) of sodium borohydride and 50 mL of anhydrous benzene. The slurry was cooled to 10 OC and 860 pL (15.0 mmol, 3.04 equiv) of anhydrous acetic acid was added dropwise so as to maintain an internal temperature no higher than 20 OC. Hydrogen evolution was measured with a gas buret. After addition of acetic acid was complete the mixture was allowed to warm to ambient temperature and stirred at that temperature for 8 h. Hydrogen evolution had ceased at 330 mL (theoretical for 3.00 equiv is 331 mL) after 5 h. The colorless slurry was filtered and the resultant white powder washed with three 20-mL portions of freshly distilled, anhydrous ether. The combined ether filtrates did not liberate hydrogen when treated with 1 N aqueous hydrochloric acid. The powder was held under vacuum over night to afford 961 mg (92%) of analytically pure sodium triacetoxyborohydride as a white, hygroscopic solid:
J. Am. Chem. SOC., No. 11, I988 NaBH4悬浮在THF中，10度以下滴加HOAcl，搅拌至没有气泡冒出即可， 得到的THF 溶液可以直接用于反应，不用再做处理。 谢谢大家[biggrin]
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