organichem - 28-4-2014 at 02:36
Hey folks, I want to prepare some BuLi - preferably in cyclohexane.
I've read several papers dealing with the preparation of BuLi in inert solvents.
Some are using Li with 1% Na, others pure Li - then some reflux after addition
of the chloroutane, or sonication is applied.
Is there anyone who has synthesized BuLi himself?
I'd appreciate a working method, I can try myself...
kristofvagyok - 28-4-2014 at 13:27
We use BuLi prepared by Sigma, but long ago the prof. attempted to make it, since we got ~50kg of Li.
Some notes before you start to prepare it:
-BuLi reacts with almost everything, even with atmospheric nitrogen.
-While making it from bromobutane and lithium a suspension of lithium-bromide forms what slows down the reaction and it's really hard to separate from
the BuLi.
-Chlorobutane reacts really slowly.
-It ignites easily upon contact with air.
AvBaeyer - 28-4-2014 at 18:37
Unless you REALLY know what you are doing and have all the proper safety equipment at hand, this is not something anyone without good lab experience
should be fooling with. Even if you can make butyl lithium, you will still need to learn how to transfer and store it. I have made a number of
organolithium reagents in my career and it is not a trivial exercise.
organichem - 29-4-2014 at 04:17
Harzard notes are substantial for BuLi - but I'm used to work with the Schlenk-technique and with pyrophoric substaces, although not with BuLi yet
(somewhere I have to begin 
)
My laboratory equipment is quite good and I've been doing home since for 7 years now (and I'm working in the chemical industries as well) 
I just wanted a more-detailed instruction how to prepare it and maybe some experiences with the synthesis?
I just started the preparation on a 90 mmol scale with US at RT expected conc. should be ~0.8 M (for the beginning)
Dr.Bob - 29-4-2014 at 05:23
I would suggest reading the article that popped up in Google from "The Preparation of n-Butyllithium" which gives some detail. Unfortunately, I can
only get the first page right now, but it gives most of the details.
http://pubs.acs.org/doi/abs/10.1021/ja01172a510
leu - 29-4-2014 at 07:56
Some articles on preparing lithium reagents are attached 
Attachment: ja01172a510.pdf (79kB)
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Attachment: Preparation of Organolithium Reagents.pdf (256kB)
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Attachment: safe.handling.organolithiums.pdf (142kB)
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leu - 29-4-2014 at 08:25
Some more articles related to butyllithium are attached
Attachment: ja00889a021.pdf (227kB)
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Attachment: ja01330a069.pdf (110kB)
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Attachment: ja01864a058.pdf (119kB)
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Attachment: ja01866a020.pdf (234kB)
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Attachment: ja01870a036.pdf (114kB)
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Methyl.Magic - 2-5-2014 at 03:38
Why do you want to use BuLi ? because sometime BuLi can be substitued with less dangerous grignard -BuMgBr reagents