教授最近丢给了我一篇 paper 要我合成新的 ligand 但是做了几次都不是很顺利 还有一些後面的步骤也不甚了解 再加上我们实验室是做无几的 没有学长会合成 所以只得上来请教大家 目前我想要合成的产物是 2,3-二甲基-2,3-二羟胺基丁烷 (2,3-Dimethyl-2,3-hydroxylaminebutane) 起始物是 2,3-二甲基-2,3-二硝基丁烷 (2,3-Dimethyl-2,3-dinitrobutane) 也就是要把硝基(R-NO2)转变成羟胺基(R-NHOH) 以下是 paper 内容 -- 2,3-Dimethyl-2,3-dinitrobutane (17.6 g, 0.1 mol) was dissolved in a mixture of THF (300 mL) and water (50 mL). Zn powder (27 g) was added all at once to this solution cooled to 8–10 °C in an ice bath. A solution of NH4Cl (43 g, 08 mol) in H2O (150 mL) was added dropwise to this slurry within 2 h, with continued stirring for 1 h at 10 °C, and the flask was stored in a fridge (4–6 °C) for 16 h. The slurry was filtered, and the precipitate was carefully washed with THF (4 X 100 mL). The precipitate was then dried by three washings with diethyl ether and carefully collected (59 g). The solution was evaporated under vacuum until THF ceased to distill off. Then the solution was protected from air, and sodium carbonate (50 g) and sodium chloride (30 g) were added with cooling. Continuous extraction with chloroform (400 mL) was performed over 18 h. A white powder was obtained (9.4 g, 63% yield), mp 182 °C. -- 而在操作的过程中出现了几个问题 第一个是 我的起始物点在 TLC 片上颜色很淡 我不太知道要怎麽去追踪说它反应完了没有 第二个是 文中有提到 The precipitate was then dried by three washings with diethyl ether and care- fully collected (59 g). 我想问的是 过滤出来的东西不就是锌粉和一些沈淀吗 为什麽还需要过搜集秤重呢 一般不是洗完滤饼後直接扔掉吗？ 第三个是 The solution was evaporated under vacuum until THF ceased to distill off. Then the solution was protected from air, and sodium carbonate (50 g) and sodium chloride (30 g) were added with cooling. 可是他不是有说要把 THF 收乾嘛 这样哪来的 solution 啊 还是这个 solution 指的是一开始加入的 50ml water 呢 又他提到的 Then the solution was protected from air 指的是要在无水无氧的环境下通氮气操作吗？ 还有最後的 extraction with chloroform (400 mL) was performed over 18 h 这边说的应该是索氏萃取(Soxhlet extraction) 而不是真的要我拿分液漏斗去摇 18 hr 吧... 但是索氏萃取不是都是固体在用的吗 还是加入 sodium carbonate 跟 sodium chloride 目的就是要让产物吸附上去做索氏萃取呢 问题有一点多 拜托大了家 感激不尽！ -- 全部旧记忆 这刻重游 http://www.wretch.cc/blog/montent By:墨水蓝 --

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