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Author Topic: Having trouble with DMSO  (Read 105 times)

T-cowboy

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Having trouble with DMSO
« on: July 05, 2011, 08:23:53 PM »
Hi

Im having som trouble getting the DMSO method (bromosafrole) to work.

I think i have the problem narrowed down to the fact that i use Kbr, instead of NaBr. At least an old topic on the hive suggests so.

I use the puglsey method, and i do keep it cold. The problem is, that it stays green, and never turns in to the red/burgundy color.

Can i somehow turn my Kbr into Nabr?

Thanks

Sedit

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Re: Having trouble with DMSO
« Reply #1 on: July 05, 2011, 10:14:25 PM »
Research some more, Pugslys an idiot armchair chemist.

Please provide me a reference for the bromination of a terminal Alkene using DMSO as a solvent.

In the process of looking for these references you may find some unexpected chemistry such as complexes that forms making this a relatively useless procedure. There is no difference between the use of KBr or NaBr other then solubility and once these are converted to HBr then non of that matters.

Do not follow pugslys method. Follow known scientific text, delete Rhodiums archives from your favorite places and research real methods instead of cook writeups.

Search REAL chemistry sites for Hydrobromination of Alkenes. You will find much more useful information then Rhodiums archives will ever give you.
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jon

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Re: Having trouble with DMSO
« Reply #2 on: July 06, 2011, 08:57:04 AM »
yeah bromoalkanes complex with dmso is one reason.
personally i have had great sucess with a method i pioneered a few years back of making hbr in-situ in acetic acid from nabr and sulfuric acid.
and many others will tell you it goes off without a hitch.
the hard part, preping dry alcolic methylamine solutions, once you got that down it gets very easy.
oh and also bromosafrole is green when dilute and concentrated it is burgandy.
you will see this during the bromination too.
but it is bi-chromatic, meaning it has different colors depending on it's concentration.

Sedit

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Re: Having trouble with DMSO
« Reply #3 on: July 06, 2011, 09:00:24 AM »
If the poster fails to provide the references for the hydobromination of terminal alkenes in DMSO like I asked this will be locked and tossed in the trash.

I will no tolerate random questions of why Rhodiums archives are not working right!
There once were some bees and you took all there stuff!
You pissed off the wasp now enough is enough!!!

Enkidu

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Re: Having trouble with DMSO
« Reply #4 on: July 08, 2011, 12:25:54 AM »
I don't care if we discuss hive/rhodium archive recipes, but at least post the original procedure and give more detail as to the problem, such as low/nonexistent yields, etc.

You can open the thread again if you add the original procedure.
« Last Edit: July 08, 2011, 12:29:52 AM by Enkidu »
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