Author Topic: Polystyrene foam and acetone ==> P2P  (Read 21424 times)

0 Members and 1 Guest are viewing this topic.

josef_k

  • Guest
Re: The yields in the introduction don't seem...
« Reply #20 on: June 04, 2004, 05:30:00 AM »

The yields in the introduction don't seem to correspond at all to the experimental section, neither does the explanation on that page, about yields.

Is it the yields that aren't true, or the procedure just doesn't work, or have I missed something?




If you look more closely you can se that they got 12.5g (0.09 mol) amphetamine from 40g (0.3 mol) phenylacetone. About 30% yield. That bit about 98% yield is probably the yield of amphetamine sulphate from amphetamine freebase.


Rhodium

  • Guest
Reduction: 30% Crystallization: 96-98%
« Reply #21 on: June 04, 2004, 11:01:00 AM »
josef_k: You've interpreted the article correctly - maybe I should clarify that in the document so that people don't mislead themselves.


Shane_Warne

  • Guest
thought so
« Reply #22 on: June 04, 2004, 08:48:00 PM »
I thought it could only have been the yield.

The amount of acetic anhydride or acetic acid to phenylacetic acid, for a 40-60% yield by experts with all the best equipment makes it less attractive.

But the apparent ease of preparing phenylacetic acid from OTC ingredients in high yields make that a good starting point. agree or disagree?

So we need a high yielding method that uses phenylacetic acid and a cheaper, more easily prepared 2nd reagent to yield P2P. yes or nah?


There's this one. That yields about 70%, but the methyllithium, requires methanol to prepare methyl iodide to prepare the methyllithium I think.
If you can acquire methanol, a bit of red phosphorus and KI, then this is for you. SWim personally has never had use for methyl alcohol, just methylated spirits and iso.


https://www.thevespiary.org/rhodium/Rhodium/chemistry/p2p.paa-meli.html



This following one uses calcium phenylacetate and calcium acetate, and the amount of acetic required (as calcium acetate) is much less.

https://www.thevespiary.org/rhodium/Rhodium/chemistry/p2p.paa-ca.html




Any thoughts on some others bees?
Because the route to P2P from phenylacetic is what's going to get you high the following week. It's best to think about it sooner rather than later, or else it's:

Pills and pain.  ;D   :(

foxy2

  • Guest
added antipolymerization additives.
« Reply #23 on: June 06, 2004, 03:36:00 AM »
added antipolymerization additives.

TBC (4-tert-ButylCatechol), BHT (butylated hydroxytoluene), TBHQ (tert-Butylhydroquinone) or (BHA) butylated hydroxyanisole are examples of some common polymerization inhibitors that should work.  Hydroquinone and other free radical scavengers might work also.


ning

  • Guest
Exactly
« Reply #24 on: June 06, 2004, 10:35:00 AM »
And given its tendency to be oxidized, I wouldn't bee surprised one bit if acetaminophen might substitute for hydroquinone in a pinch.... ;D

I read somewhere that calcium acetate can be used to produce p2p from phenylacetic acid. This is a much more attractive option to my mind than lead or acetic anhydride.

Perhaps one could perform the operation sequentially--after acidic hydrolysis of phenylacetic acid and H2O2 precipitation of sulfur, the mixture would be filtered to remove sulfur, leaving a mixture of ethanol, water, ammonia, hydrogen peroxide, and phenylacetic acid.

A small amount of copper sulfate or MnO2 (or KMnO4) would be added, to catalyze the destruction of the remaining H2O2, (either turning it to O2, or oxidizing the ethanol to acetic acid), then the requisite amount of calcium base (lime or chalk) could be added, and an appropriate quantity of vinegar, and the whole shebang distilled to remove all fluids. This would strip off the ammonia, alcohol, and water. Then, once the last bit of water left, the reciever could be changed, and a vacuum applied. P2P would start to be collected, until the reaction completed.

Since this implies even a one-pot reaction is possible, it might minimize contact with the foul phenylacetic acid. No acetic anhydride necessary.

One might be tempted to take the p2p collected and throw in some oxalic acid or formic acid and ammonia, for a leuckart reaction, following Zealot's fine instructions. How delicious!

Well, that's enough wild speculation from me ;)


pink_dust_angel

  • Guest
what exactly does the sulphur do in this ...
« Reply #25 on: June 13, 2004, 11:40:00 AM »
what exactly does the sulphur do in this reaction..ive seen the Willgerodt reaction but this reaction is not a Willgerodt as i understand.if the sulphur is turned to H2S then im ok..can some knowledgable kind person give a balanced equation?
yes i did check all the posts but only one i found that had equations(apprently) was a dead link  >:(

ning

  • Guest
It is.
« Reply #26 on: June 13, 2004, 05:30:00 PM »
Go look on rhodium's page. You will see that they are the same.

If one were to use another oxidizer along with the sulfur (like H2O2), then it would be a "catalytic transfer wilgerodt reaction", operating in much the same way as a wacker oxidation, with the sulfur temporarily being reduced to H2S before becoming oxidized back to sulfur again.

Since the wilgerodt reaction works on all manner of materials, including alkenes and alkyl ketones, I very much suspect that it would work with H2O2 included. Would be fun to try.

Also, I don't think the reaction emits H2S vapors during the oxidation even though it is generated during the oxidation of styrene, because the H2S reacts with the included ammonia to form ammonium sulfide. When the reaction mixture is hydrolyzed and acidified is when the H2S should be released, so addition of oxidizing agents to the hydrolysis to scavenge the H2S as it is released should take care of the major smell component (I hope ::) )

The wilgerodt is potentially very OTC and bulk-capable, so I think it deserves some careful attention.


callen

  • Guest
P2P...the old way
« Reply #27 on: June 13, 2004, 05:36:00 PM »

pink_dust_angel

  • Guest
ok ive checked 3 organic text books and 1...
« Reply #28 on: June 14, 2004, 02:37:00 AM »
ok ive checked 3 organic text books and 1 inorganic and there is nothing in any of them about Wilgerodt-Kindler
wilgerodt or kindler....i googled Wilgerodt-Kindlerand got 3 results non of which gave a reaction mechanism or anything of the sort.
the thing thats confusin me is that the Wilgerodt on rhodium shows the compound produced to contain sulphur while the one on this thread seems to produce simple phenylacetamide...... :(


Organikum

  • Guest
spare the time searching bees
« Reply #30 on: June 14, 2004, 03:41:00 AM »
The link:

Post 282823 (missing)

(callen: "the "Great Bear" method", Newbee Forum)
)

Forget it, not worth to look at. This was covered better all over.
ORG


Shane_Warne

  • Guest
I read somewhere that calcium acetate can be...
« Reply #31 on: June 14, 2004, 04:35:00 PM »
I read somewhere that calcium acetate can be used to produce p2p from phenylacetic acid. This is a much more attractive option to my mind than lead or acetic anhydride.

Mine too. I wrongly thought that calcium acetate was one of the acetates that was harder to prepare, but it can actually be done with vinegar an CaCO3. Making it the easiest method imho.

But trying to prepare the correct amount, in situ, with unknown % vinegar would be totally rediculous. Especially for beginners. (like swisw)  ;D

As far as H2S goes, the H2O2 is a good partial remedy, but because H2S is so dangerous, and such small amounts can be detected, a fume hood with carbon filters should be essential.

Even a nanoscale testrun is going to cause problems with the local inhabitants, I'd imagine. If you've ever accidently left a bit of pfed.sulfate in an RPI then you'll know what I'm talking about.

It isn't difficult finding proper fireproof, and chemical proof fans with appropriate ducting in the one shop.

But about the H2O2, I like the idea myself. So you don't think it would detrimentally effect the hydrolysis at all?


Does polystyrene dissolve in styrene monomer, or are they easily separated if some of it polymerizes?

It'd be cool if your right about acetaminophen/paracetamol ning.  ;)


Here's the calcium phenylacetate and calcium acetate reaction again. It requires a really easy fractional distillation of the 3 ketones in produces, one valuable (P2P/benzyl methyl ketone).

https://www.thevespiary.org/rhodium/Rhodium/chemistry/p2p.paa-ca.html



It needs to be experimented with, to find out what the ratio of the products (3 ketones) typically is. Sounds good anyway.

What does the author mean by, "a sulfur vapor bath"?

ning

  • Guest
Hmmm
« Reply #32 on: June 14, 2004, 05:49:00 PM »
Good catch, that link. I couldn't find it :-[


But trying to prepare the correct amount, in situ, with unknown % vinegar would be totally rediculous. Especially for beginners.



I doubt a p2p synthesis is a good idea for beginners anyway. But, umm....at least where I live, all vinegar is labelled with its percentage. 3%, if I remember correctly. It doesn't really matter, because you can always titrate the pH to neutral with litmus paper. Or, to be even easier, if you are using calcium carbonate, just add until there's no more bubbling from CO2. I don't think even beginners would have trouble with that.


But about the H2O2, I like the idea myself. So you don't think it would detrimentally effect the hydrolysis at all?




No. Both phenylacetic acid and p2p are at the highest state of oxidation they can reach by normal means. Only beastly things like boiling nitric acid, concentrated peracids, and permanganate would be able to oxidize them more (and of course molecular oxygen, suitably heated 8) )


Does polystyrene dissolve in styrene monomer, or are they easily separated if some of it polymerizes?


Dunno, but I reckon the wilgerodt reaction will produce enough tar on its own, so I would say just throw the crude styrene directly into the oxidation, then use the fact that the product is an acid and water soluble to effect the purification. I don't think the polymerized styrene's going to affect anything. It's plastic, after all!

I don't even think one would need to call it a fractional distillation...

I hear that the yield in that reaction goes up when it is performed under vacuum to immediately suck up the formed p2p. To something like 70%. Wow.

Really, really, guys. If the twin evils of sulfurous smells and need for pressure in the wilgerodt reaction can bee overcome, I think we have a winner. P2P from plastic. Can it get any sweeter than that?




Shane_Warne

  • Guest
chatter
« Reply #33 on: June 15, 2004, 12:12:00 AM »
I doubt a p2p synthesis is a good idea for beginners anyway. But, umm....at least where I live, all vinegar is labelled with its percentage. 3%, if I remember correctly. It doesn't really matter, because you can always titrate the pH to neutral with litmus paper. Or, to be even easier, if you are using calcium carbonate, just add until there's no more bubbling from CO2. I don't think even beginners would have trouble with that.

;D  ok ning, you get cute with your one-pot design.

I doubt you'll get it to work though, as you won't be able to see many bubbles as it gets along, especially as the amounts of water increase 10 fold.

As the concentration of your 3% vinegar goes down, CaCO3 and Ca(OH)2 will fail to dissolve, and it'll just sit there.

I've found that usually when making acetates with vinegar, there's usually leftover carbonate, upon crystallization, and it needs to bee recrystallized with vinegar to convert it.

Besides, making it with vinegar (not in situ though) is only suitable for a microscale test run.

Then again, buying vinegar is a lot less unpleasant than buying those aweful pills!@

Dunno, but I reckon the wilgerodt reaction will produce enough tar on its own, so I would say just throw the crude styrene directly into the oxidation, then use the fact that the product is an acid and water soluble to effect the purification. I don't think the polymerized styrene's going to affect anything. It's plastic, after all!

Good! really good.


I hear that the yield in that reaction goes up when it is performed under vacuum to immediately suck up the formed p2p. To something like 70%. Wow.

Do you know by any chance, if vacuum replaces CO2?
Then we'll have: polystyrene foam, vinegar, chalk and a hoover deluxe ;D


Really, really, guys. If the twin evils of sulfurous smells and need for pressure in the wilgerodt reaction can bee overcome, I think we have a winner. P2P from plastic. Can it get any sweeter than that?

Not really, it's a winner. Especially now that we've put pen to paper and sorted out the route to P2P, to move forward on. You've helped a LOT. ORG aswell, and everyone else.

I wonder if a pressure cooker, with it's pressure release valve sealed, would do the trick?
They are normally stainless steel or aluminum alloy.

Osmium

  • Guest
Why don't you people try out the original...
« Reply #34 on: June 15, 2004, 02:32:00 AM »
Why don't you people try out the original literature synth before getting all excited about the many tweaks and improvements that might (more likely: might not)  work?


ning

  • Guest
Of course
« Reply #35 on: June 15, 2004, 10:18:00 AM »
That's the natural thing to do. You could help ;)

Since they need the reaction run at 95 C (IIRC), and ethanol boils around 80, it may be possible to achieve the desired temperature using a reflux apparatus. A pressure cooker could very likely do it as well, but of course it would have to be a stainless steel one. (Hot boiling oxidizing mixture, not good) Which might not be such a bad investment, really.

I'd say, try the reflux first. Monitor the bath temperature and see if it can get high enough. If that fails, then go hunting for a pressure cooker.

And I only suggested one pot (actually two pots) might be possible, reusing the same apparatus. Of course nothing is ever quite that simple, but...whatever ;D

Well, rural bees, let's see what ya got!


pink_dust_angel

  • Guest
am i correct in assuming that the ethanol is...
« Reply #36 on: June 17, 2004, 11:21:00 AM »
am i correct in assuming that the ethanol is just a solvent in this reaction?am i also correct in assuming ethanol can be reploaced by another solvent like methanol or isopropenol?yah i found the alternate reaction with just (NH4)2S and water 8)  (sans ethanol though >:( )

Shane_Warne

  • Guest
am i correct in assuming that the ethanol is...
« Reply #37 on: June 17, 2004, 02:59:00 PM »
am i correct in assuming that the ethanol is just a solvent in this reaction?am i also correct in assuming ethanol can be reploaced by another solvent like methanol or isopropenol?

I'd assume so. The ethanol and NH4OH solution would be good solvents for the sulfur, at elevated temperature and that's probably why they were chosen.

SWIM would just use denatured, because EtOH, straight EtOH isn't common in Oz, and it's just more hassle.

Plus, considering the yields and feedstocks cheap price, other than controlling the smell, there shouldn't bee too many problems.


http://www.azom.com/details.asp?articleID=1177#_Sulphide_Stress_Corrosion



I've never seen a stainless steel that remains stainless for too long.

I suppose you could sit a teflon coated saucepan in there, and hope it adds to it's life, or to put it better...to add to the life of the 100bux you fork out for the single-purpose pressure cooker.

A teflon coated pressure cooker, with a pressure gauge and built in digital thermostat would bee perfect. Talk about cooking in style! Joy!  8)

Working on a design to concentrate vinegar, using a hybrid between the setup at Orgsyn and a toaster  ;D .
 
It'll use 3 glass bottles, copper tubing, copper condensor to recycle acetone.
The nichrome wire can sit in the first glass where acetone drips, so that short circuiting isn't a problem.

ning

  • Guest
Actually
« Reply #38 on: June 17, 2004, 07:16:00 PM »
If it in fact turns out that the limiting factor is only the boiling point of the alcohol, it might well bee the case that the reaction can be run in a reflux apparatus.

(the isopropanol/water azeotrope boils at ~80 C, ethanol+water ~78 C)

Hey, LWR meth bees! What kind of temperature differential can you get from the bottom of the reaction vessel to the top of the refluxing solvent in the condenser? Greater than 15 degrees? Let's hear it!


p2e3r4f5e6c7t8

  • Guest
Hey shane and all my other brothers in OZ.
« Reply #39 on: June 17, 2004, 09:53:00 PM »
Hey shane and all my other brothers in OZ. :)
What the fuck do you mean that EtOh isent common in OZ  eehheemmm, BULLSHIT :o , Look a little harder my freind :P .
And just one other question?, Why in another post hear do you say yoy want to concentrate vinegar, If its acetic acid your after then look a lil harder again because it sold as a crystaline salt in little canisters ;)
If you do get stuck with it then PM me my OZ brother ;) and ill do what i can to help ya out as far as steering you in the right direction to find what your looking for ;)
:P  :P  :o  ::)  :P