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铜虫 (初入文坛)

应助: 2 (幼儿园)
金币: 116.5
红花: 2
帖子: 47
在线: 9.2小时
虫号: 979703
注册: 2010-03-23
性别: GG
专业: 高分子合成化学

[求助] 通过4-甲苯磺酰氯制备环氧的注意事项

最近在做含环氧单体合成，先用4-甲苯磺酰氯保护端羟基，再按下面的方法使其生成环氧。人家文献里已经做出来了，我重复好几遍都不对，不知道问题出在那里，希望牛人指点迷津。
文献的步骤是：
1.The monomer（8.93g） was dissolved in acetonitrile-water (2:1, v/v, 45 mL) then added a small amount of phenolphthalein.
2.The solution was maintained at 35-40 °C and titrated with 5 M sodium hydroxide solution to a faint pink color.
3.The solution was divided into two equal portions, and each was slowly added with stirring to a suspension of sodium carbonate (40 g) in ethyl acetate (150 mL). 4.The solid was filtered off and the combined filtrates were dried over magnesium sulfate.
5.The solvent was removed under reduced pressure at room temperature to a small volume.
我做的时候第一步正常;第二步怕判断不准用了PH试纸，指示在8.0到9.0之间；第三步slowly added 我是直接倒的，45ml 用了2分钟吧；第五步没什么问题；第六步室温下旋转蒸发，得到粘稠液不是固体，用乙醚洗出白色沉淀，测试NMR不对苯环峰没消失
现在我想各位虫友帮着分析分析是那块有问题个人觉得是碱的量没把握好可是环氧在碱中也不稳定啊还有地三步是起什么作用
本人木有金币还请各位见谅