zhouxiaogui
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On the reaction of chlorogrignard reagent with o-chlorobenzonitrile
Why do I use chlorocyclopentane to make Grignard reagent and o-chlorobenzonitrile to make ketone with low purity. I added the solution of
o-chlorobenzonitrile and toluene dropwise at 80 ℃, heated it at 100 ℃ for 6 hours, and then added hydrochloric acid dropwise at room temperature
for hydrolysis. The purity of ketone is not high enough. I want to ask you whether the dropping temperature of my o-chlorobenzonitrile solution is
wrong? Do you need a higher temperature drop or a lower temperature drop? thank you
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njl
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This website has a good reference. Look there and you'll find what you're doing wrong.
Reflux condenser?? I barely know her!
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clearly_not_atara
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Since you're preparing the Grignard reagent from chlorocyclopentane, I suspect the preparation may not be working well enough. You can titrate the
Grignard solution in order to make sure there is actually enough C5H9MgCl before you start the coupling reaction.
Unfortunately, 100% theoretical yield is probably not achievable in this reaction, because of the unavoidable transmetalation side reaction with the
aryl chloride moiety. But a good enough yield is still possible.
[Edited on 04-20-1969 by clearly_not_atara]
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zhouxiaogui
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Quote: Originally posted by clearly_not_atara  | Since you're preparing the Grignard reagent from chlorocyclopentane, I suspect the preparation may not be working well enough. You can titrate the
Grignard solution in order to make sure there is actually enough C5H9MgCl before you start the coupling reaction.
Unfortunately, 100% theoretical yield is probably not achievable in this reaction, because of the unavoidable transmetalation side reaction with the
aryl chloride moiety. But a good enough yield is still possible. |
I forgot to say that I added 2% mol of cuprous bromide before dropping o-chlorobenzonitrile
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zhouxiaogui
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thank you
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