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Topic: Azeotropes  (Read 1795 times)

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Offline phth

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Azeotropes
« on: October 19, 2015, 11:37:11 PM »
Anyone using benzene to azeotropically dry a non-volatile substance? 

Offline Arkcon

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Re: Azeotropes
« Reply #1 on: October 20, 2015, 07:34:27 AM »
Toluene can be used to quantitatively determine moisture in a sample, by distilling over its azeotope with water.  You can read that procedure in the USP.  I suppose benzene trinary water-ethanol-benzene azeotrope could be used to dry something.  But this might be destructive to the dry solid.
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline TheUnassuming

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Re: Azeotropes
« Reply #2 on: October 20, 2015, 04:30:27 PM »
I usually azeotrope materials with benzene before I run certain reactions.  Some reactions I don't bother unless I'm trying to squeeze every last % yield (lithiations ect), others like catalytic organometallic reactions and enantioselective (CBS) reductions it seems almost required to get even reasonable yields/ee's.
When in doubt, avoid the Stille coupling.

Offline phth

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Re: Azeotropes
« Reply #3 on: October 20, 2015, 11:49:54 PM »
Thanks Arkcon, TheUnassuming!

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