小中大[求助]如何除去DMF和DMSO?
这里请教各位老师和有机合成高手:
我反应的体系是无水DMF和DMSO,
到最后,按照文献类似的做法是,减压除去DMF或DMSO,然后加入三乙胺乙酸(1M,pH=6.5)后, 跑HPLC(A三乙胺乙酸(0.1M)和B乙腈,10-20%梯度),得到淡黄色固体,收率只有29%。
但是,实验室油泵坏了,我实用水泵加热到70°C也不见减少多少DMF和DMSO,而且一直担心加热对产物(含有喹啉酮)有极大影响。后来,我给作者写信了,他说:”To answer your questions, it is relatively easy to remove DMF. Under vacuum with a liquid nitrogen trap, DMF can be removed in a short period of time at room temperature. For DMSO, it is a little bit hard to remove it. But for a long period of time under vacuum, you can still remove it. However, this is not a problem for us. We did HPLC purification. DMF or DMSO as solvents have been separated during this purification process.“
这里有问题请教:
1,如果是梯度离心,最后如何除去冲洗后的三乙胺乙酸和乙腈?
2,淡黄色固体如何得到?是分离后就沉淀出来?不会堵塞柱子么?还是减压蒸馏?但三乙胺乙酸如何除去呢?
3.按照作者回复,采用” a liquid nitrogen trap“可除去,这玩意是啥东西?我们一般的冷冻干燥是同一个效果么?
4.作者回复是否可理解为:只要稍微除去DMF或DMSO即可,因为后续的HPLC也可除去,对么?
先多谢了!