求教丁基锂拔溴上二氧化碳没产物？ 描述：底物如图，11到12 1,8-Dibromo-3,6,9,9-tetramethyl-9,10-dihydroacridine(790 mg, 2 mmol) and Et2O (25 mL) were added to a flamed dried three necked flask equipped with a dropping funnel containing n-BuLi (8.8 mmoL). The mixture was cooled to –40 oC and the n-BuLi was added dropwise. The mixture became clear and turned yellow. After the additon, the mixture was stirred at room temperature for 3 h. Then the solution was cooled to –40 oC again and dry CO2 was bulbed into the solution for 1 h. The mixtrue was treated with 2 N HCl (aq), and the solid was collected through filtration. After being washed with petroleum ether, the desired product was obtained as yellow solid (511 mg, 79% yield). 按照文献做，加完 丁基锂 是黄色，搅拌时间2个小时左右，无论是低温（-40或者-78）还是常温，或者0度，时间长了体系就变黑了，不知道是不是坏了 用THF做溶剂的话，-78下，加完丁基锂立刻变黑 现在就干脆低温-78下，乙醚溶剂，加完丁基锂后低温保持1小时，加干冰，然后加酸后处理，萃取，原料是没了，但是感觉没什么产物 求指点，丁基锂-78一个小时够不够拔溴，还有什么要注意的吗 溶剂都是现蒸，肯定 无水 有一篇类似文献是这样的，加TMSCl，不知道是不是为了保护NH，不知道我那个NH是不是要保护，而一样底物也就只有那一篇文献 求高手指点！ 查看更多5个回答 . 18人已关注
审稿人质疑磁固相萃取材料中Fe3O4分布不均匀，请问该如何答复对方？How to ensure that Fe3O4 is evenly distributed on the carbon material？ If some parts of the carbon material fail to adhere to Fe3O4, are these parts unable to conduct magnetic separation? 我的实验现象是用磁铁回收材料时没有出现明显的材料损失，但审稿人认为，如果有些碳颗粒没能结合Fe3O4，就会在回收材料时发生损失，请问如何严谨的答复对方，求大佬给些指导谢谢，第一次投稿没什么经验查看更多1个回答 . 6人已关注
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