Sciencemadness Discussion Board

Sterogenol solution

dome13 - 27-6-2020 at 07:04

Hello!
I recently got some very old stuff. The label says it is "Sterogenol solution". Who gave me said it is iodine solution, because it has a deep brown color. I checked the ingredients on label and the main component besides distilled water is cetylpyridinium bromide. (There is no iodine after all.)

My quiestons:

- Can I separate it with a simple distillation?

- Is there any organic reaction with cetylpyridinium bromide, wich can be interesting? (I didn't really found anything...)

Syn the Sizer - 27-6-2020 at 08:41

Just a thought, I see a few useful things in cetylpyridinium bromide. There is a bromide ion, a a hexapyridinium. You could possibly add some HCl to produce the chlorine salt and HBr, then oxidize the HBr to Br2. This will leave you with hexapyridinium chloride. After you can use base hydrolysis with NaOH to produce hexadecanol, pyradine and as a byproduct NaCl.

Or maybe it might be better to do the base hydrolysis first and have NaBr as the byproduct then double replacement with HCl and oxidize to bromine.

This is just theoretical and I don't know if it will work. But if it does, you will have bromine, pyradine and a 16 carbon long chain alcohol which have many uses.

I hind sight HCl probably wouldn't work you would need H2SO4

[Edited on 28-6-2020 by Syn the Sizer]

Syn the Sizer - 27-6-2020 at 18:19

I was thinking about this today. What personally would do is a base hydrolysis with NaOH. I would then distill the solution, discarding anything below 113oC and collecting everything between 113oC and about 118oC. This should be your pyridine.

I would then wash the hexadecan-1-ol with water to extract the NaBr. The alcohol is insoluble in water. You could then use that to synthesize your Br2, here is a UC235 video on it.

https://www.youtube.com/watch?v=AL9ehxTaYRs

Purifying the alcohol will be a little tougher since it has a boiling point of 344oC. But I quick Wikipedia search shows it it is soluble in acetone. You could dissolve it in acetone then crash it out with water, might work. From there distill up to 200oC and collect the residue in the distillation flask.

But that's me, I would get more use out of those 3 products. This is also if you have a distillation set to do all this.

Edit:
If anybody has better temperature ranges for distillation please add.

[Edited on 28-6-2020 by Syn the Sizer]

Boffis - 28-6-2020 at 00:09

@Syn the Sizer; are you sure about being able to split off the cetyl C16 alkyl group from a quaternary pyridine compound by simple alkali treatment? Such compounds are rather stable and when they do react they often undergo rather unexpected reactions. Some quaternary pyridine compound suffer ring opening rather then the formation of the free base while others suffer attack in the 2 position to give (in your case) a hydroxypyridine which undergoes tautomeric rearrangement to a cyclic secondary amide. Do you have a reference or an example of this type of reaction?

OP: is cetylpyridinium chloride not a phase transfer catalysis?

[Edited on 28-6-2020 by Boffis]

mackolol - 28-6-2020 at 04:30

Quote: Originally posted by Syn the Sizer  
Just a thought, I see a few useful things in cetylpyridinium bromide. There is a bromide ion, a a hexapyridinium. You could possibly add some HCl to produce the chlorine salt and HBr, then oxidize the HBr to Br2. This will leave you with hexapyridinium chloride. After you can use base hydrolysis with NaOH to produce hexadecanol, pyradine and as a byproduct NaCl.

Or maybe it might be better to do the base hydrolysis first and have NaBr as the byproduct then double replacement with HCl and oxidize to bromine.

This is just theoretical and I don't know if it will work. But if it does, you will have bromine, pyradine and a 16 carbon long chain alcohol which have many uses.

I hind sight HCl probably wouldn't work you would need H2SO4

[Edited on 28-6-2020 by Syn the Sizer]

For me it would be just a waste of time and reagents. You won't be able to purify the pyridine enough to be useful as it is very very hygroscopic. The same with the rest of reagents and quantities will be low even if you really manage to success. And after all it is just destroying useful compound for nothing, as getting pyridine as well al bromine isn't really a problem.
Maybe check its properties as a phase transfer catalyst as Boffis has said or its antiseptic properties if you like to play with microorganisms.

Syn the Sizer - 28-6-2020 at 05:11

Quote: Originally posted by Boffis  
Do you have a reference or an example of this type of reaction?
[Edited on 28-6-2020 by Boffis]


Well yes and no, but it was from memory based on pyradine from piperine. I cannot find the original article I read and the laptop it was on is now screwed. But I did fine another forum post on the synthetikal backup. I was incorrect in my memory, the base was used to split piperidine from piperine not pyridine from piperidine, sulfuric acid and 300oC was used to split off the pyridine.

I did also mention in my first reply I am not sure if this would work, I thought about it on and off throughout my day and decided to post again before bed. I do not have much experience with pyridine ore other nitrogen compounds.

draculic acid69 - 29-6-2020 at 01:54

Quote: Originally posted by Syn the Sizer  
Quote: Originally posted by Boffis  
Do you have a reference or an example of this type of reaction?
[Edited on 28-6-2020 by Boffis]


Well yes and no, but it was from memory based on pyradine from piperine. I cannot find the original article I read and the laptop it was on is now screwed. But I did fine another forum post on the synthetikal backup. I was incorrect in my memory, the base was used to split piperidine from piperine not pyridine from piperidine, sulfuric acid and 300oC was used to split off the pyridine.

I did also mention in my first reply I am not sure if this would work, I thought about it on and off throughout my day and decided to post again before bed. I do not have much experience with pyridine ore other nitrogen compounds.


The piperine split happens bcoz there's a double bond that gets broken I think.it doesn't work the same way for a fully saturated alkyl chain. But where n, demethylation works maybe n, dealkylation works. I don't know much about whether the much longer alkyl chain makes the n, dealkylation not happen but that's what you want to achieve to yeild pyridine + cetyl whatever.ethylcloroformate is one such method I think. Also I think making the n-oxide then using iron sulfate is another n, demethylation method. The polonovski reaction might have something to do with this.
These are the things I'd look into to remove the alkyl chain if I wanted to seperate pyridine from the solution

Syn the Sizer - 29-6-2020 at 06:18

Quote: Originally posted by draculic acid69  
The piperine split happens bcoz there's a double bond that gets broken I think.


You are correct. After re-reading a procedure and looking at the piperine molecule again I realized I got ahead of myself in my suggestion. I always forgot the stability of many nitrogen compounds and should do more reading. Get prepared for the coming years of school.

[Edited on 29-6-2020 by Syn the Sizer]