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womble
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P2P from recycled styrene?
From my limited reading on the subject, I have noted the capacity for oxidation type reactions to proceed rapidly to the carboxylic acid derivative of
the aldehyde. Thus, I propose a novel route to P2P.
1. Styrene can be reclaimed from styrene & polystyrene containers as per the following patent.
http://www.patentstorm.us/patents/6500872-claims.html
(Limonene is suggested as the organic solvent; there is another that suggests using styrene itself – although you probably couldn’t unless you
already had some?)
2. Styrene can be oxidised to its epoxy derivative as per the following patent (gas-phase/pipe bomb).
http://www.patentstorm.us/patents/4894467-description.html
(One of the problems with which process is over-oxidisation)
3. Styrene Oxide / epoxide shows a tendency when being studied to isomerise to phenylacetaldehyde.
http://www.rsc.org/delivery/_ArticleLinking/DisplayArticleFo...
Surely if it has a tendency to do so, this could be exploited ie. Intentionally inducing isomerisation to the aldehyde (seems to be a product of
oxidation anyway).
4. If the styrene oxide, when subjected to further oxidisation, forms the aldehyde, further oxidisation would, logically, form the carboxylic acid,
phenylacetic acid?
http://www.erowid.org/archive/rhodium/chemistry/p2pol.styren...
(This is provided as it shows the linkages of the styrene oxide, I really don’t want to fuck with grignard’s)
5. Phenylacetic acid and acetic acid (+ catalyst) = P2P
http://www.erowid.org/archive/rhodium/chemistry/p2p.phenylac...
6. In much the same way that benzoic acid + propionic acid = propiophenone (decarboxylation), to which reaction the following patent pertains:
http://www.freepatentsonline.com/4172097.html
This too is carried out in the gas phase, which appears to avoid the ‘tar’ accompanying the liquid-phase reactions.
(Not sure that I would want to scale this sucker up, 650 pounds / hour should be ample)
I am assuming of course that styrene oxide could be intentionally overoxidised, or isomerised, and that the product would in fact be phenylacetic
acid. I am also assuming that P2P could be produced through the same gas phase reaction, containing the two carboxylic acids, that works for
propiophenone.
If it works it would seem to be a perfectly legitimate exercise in recycling (right up until some irresponsible person mixed methylamine with it
anyway). I am aware that this couldn’t possibly be the simple solution (albeit scary reactions) that it looks like, can someone tell me why?
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tupence_hapeny
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Here is an electrochemical synthesis of phenyl-2-propanone from this year, it uses benzyl bromide, acetic anhydride and platinum electrodes in an
undivided cell, with 80+% yields.
http://www.rsc.org/publishing/journals/GC/article.asp?doi=b6...
Can someone please grab this article for me (I know this is a post re: styrene to P2P, however, it is still the same end product is it not).
Womble,
The limonene looks like the way to go, I cannot find anywhere where acetone alone will dissolve all the polymer, a mix of acetone and MEK will, but
that's no good.
Can anyone draw up a procedure from start to finish - Styrene (+Limonene) = Styrene monomer + (NaOCl + NaBr (10:1)) = styrene oxide (NB TS-1 Zeolite
or mordenite with Ti & HF = styrene to Phenylacetaldehyde in one step) - isomerization with SiO2 gel (gas phase) = phenylacetaldehyde + oxidation
(HOW for quick & easy?) = phenylethanoic/acetic acid
tup
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Sauron
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I see. So all that blather about what to do about the drug war, and how much amateur science was threatened, etc etc was just so much eyewash because
here you are cooking P2P.
Hypocrite!
Just another fucking meth cook.
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The_Davster
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Quote: | Originally posted by Sauron
I see. So all that blather about what to do about the drug war, and how much amateur science was threatened, etc etc was just so much eyewash because
here you are cooking P2P.
Hypocrite!
Just another fucking meth cook. |
Yeah I was just thinking this myself...
You are on some thin ice now with me, TH...
[Edited on 4-4-2007 by The_Davster]
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Sauron
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You know, we deal with a lot of dual-use (or multiuse) compounds on this forum. Acetic anhydride has a host of uses other than making heroin and
anyway you can't make a damn bit ot that if you don't have morphine to acetylate. Same goes for acetyl chloride.
Same goes for benzaldehyde. Lots of other things too. There's room for doubt, and no reason to presume that someone is up to drug cookery. Piperidine
for example has a bad rep because of PCP but it's also a very necessary deprotection reagent in Fmoc peptide chemistry.
However I have yet to hear of any great synthetic use for phenylacetone (P2P) other than making amphetamines. Oh, there may be some, but in a minor
key and nothing than can't be worked around.
It has some industrial uses but nothing pertinent to amateur chemistry AFAIK. Just one famous illicit use.
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madcease
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Does anyone have any results regarding this???
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not_important
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The first patent given does not appear to deal with depolymerising polystyrene, but rather simply converting waste PS into clean, compact
polystyrene.
Phenylacetic acid is useful in making pleasant smells. Its esters with shorter chain alcohols smell honey-like, often with overtones of rose. As the
alcohol chain length increases the order shifts toward chocolate, sometimes with light floral hints of rose or orange, and then moves on into
balsamic. The esters of phenethyl alcohol are rose-like for the short carboxylic acids, often with overtones of honey, move on into 'green' oders with
floral hints, and becoming green-buttery with longer chains.
I once made both the acid and alcohol from polystyrene. Polystyrene foam can be compactified by heating it. This can be done in an oven, or with waste
hot air from a kiln. The polystyrene con be converted to monomeric styrene by destructive distillation, best done under reduced pressure and/or blue
to UV light. The distillation receiver should have a small amount of an antioxidant in it. The crude monomer is redistilled, again with antioxident
in the receiver, to give a misture of styrene and ethylbenzene. This is converted to phenylacetic acid via the Willgerodt reaction or one of its kin;
some of the ethylbenzene will react and a small amount won't. The acid will be in the form of the free acid mixed with the amide, or mostly as the
thioamide for the modified Willgerodt reactions.
[Edited on 6-4-2007 by not_important]
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tupence_hapeny
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So, I can't work out a way to make shit?
MY pastime is now, in this country, illegal for the duration of the war on drugs and I am supposed to be utterly unconcerned with how long that takes?
If people want to make the stuff, I say let them, in fact, help them. Because quite frankly, they are at least (obviously not intentionally)
demonstrating the stupidity of the current approach, by making their way to illicit substances using chemicals other than those denied me in order to
prevent them achieving that purpose.
Quite simply, I personally do NOT care if they use up all the bloody styrene in this country, for once they would do me and others a service - making
recycling work... The sooner it becomes blindingly fucking obvious that prohibiting amateur chemistry is not going to work, the better I'll like it.
People making their own phenylacetic acid from styrene is a small start, and P2P from there, is a slightly bigger one, but IT IS a start
We are all the sum of our experiences, and our reactions to the same
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Sauron
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All you are doing is wingeing about your criminality being, after all, criminal.
You are not an amateur chemist, you are a criminal and apparently proud of it.
So tell the judge you are proud of it when they incanrcerate your ass.
You do not speak for honest chemists.
You are a criminal.
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Levi
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Quote: | Originally posted by Sauron
All you are doing is wingeing about your criminality being, after all, criminal.
You are not an amateur chemist, you are a criminal and apparently proud of it.
So tell the judge you are proud of it when they incanrcerate your ass.
You do not speak for honest chemists.
You are a criminal. |
According to the law, a large amount of the "honest chemists" on this board are criminals. Why should TH be worse than the rest? You call him a
criminal because you believe he is doing something immoral whereas you feel that the "honest chemists" are being victimized. Nobody held a conference
to determine who would be allowed into the honest chemist club. As far as I'm concerned, if he's posting intelligent information and is interested in
the chemical theory behind the synthesis, then that makes him an honest chemist. It's the people with no concept of chemistry who just want an easy
recipe for whatever drug they are addicted to that are the ones we should flame here. Additionally, while I don't think psychoactive drug making is
the purest form of chemistry, it is chemistry (and a several notches above the k3wl b0mb makers if you ask me).
Chemcrime does not entail death. Chemcrime is death.
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Sauron
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Bullshit. He's out to turn this into a meth cook's kaffee klatch, swapping recipes for P2P. And all the time spouting garbage about the moral high
tone he is upholding.
I call him a criminal not because what he advocates is immoral, but because what he advocates is blatantly and severely felonious in his own country
and by his own statements.
There's a big difference between him and those of us who might be bending the rules here and there.
If he wants to come on here and talk chemistry, that's what this is for, but he was not talking chemistry was he?
He was talking advocacy of blatant criminality. Also a lot of claptrap about how drugs don't hurt anyone. Well, I've seen a lot of people hurt by
drugs. Like by the meth cut with strychnine and weed killer (paraquat) in Thailand. The DEA didn't put it there, the fucking dealers did.
I've known people who died of cocaine heart.
So tell me again about how drugs are harmless.
And I'll call you a liar.
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Nicodem
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Quote: | Originally posted by Sauron
There's a big difference between him and those of us who might be bending the rules here and there.
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It seems tasteless that the one accusing Tupence is the same one who started a thread like this. Or, should I say: "Let the one who is without sin throw the first stone."
Though I do not like Tupence, mainly because he sounds like Synthetikal on medication and with a spell checker and find his apologetical ideology
disgusting, I still do not consider someone discussing how to make illegal drugs a criminal. His attitude certainly is hypocritical, but what is
discussing about making illegal drugs in comparison with discussing about making weapons of mass destruction? Comparing a wanabe mass murderer with a
wannabe meth cook is like comparing Saddam or Bush with your local meth cook or heroin diller. So where is that "big difference" you talk about?
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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Levi
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Unless someone is being forced to do drugs, whatever the outcome, the responsibility rests with the individual. If they die from it that is their
responsibility. If they go blind, become incontinent, stop sleeping, ruin relationships and/or are unable to become sexually aroused, the blame rests
completely with the individual. Drugs do, indeed, cause harm... as do cars, hammers, airplanes, bacteria, pollution and broken condoms.
I do not want to see this forum become a hangout for stoners any more than you do but I think your statements attacked him before he actually said
anything highly inappropriate. I must admit, though, I missed his request for a "quick & easy" procedure "from start to finish" on my first read.
The rest of his comments, though, about whether or not a certain solvent would work better than another was within the realm of legitimate chemistry,
and I'm interested in whether or not such a procedure actually exists. The way I see it, if a synthesis for whatever drug is discovered which is
simple and performed entirely with common OTC items, it will become impossible to stop and therefore there need be no more need to ban useful
chemicals.
Chemcrime does not entail death. Chemcrime is death.
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tupence_hapeny
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Ummm,
Is it possible to get this entire conversation, re: legal, social, moral and ethical out of this board please?
Levi,
You are on the money, I don't see it as likely that ANY government will ban styrene (more IS the pity). Point being, if it possible to establish that
the substances that the government wishes to fight anyone making - by banning legitimate amateur chemistry (which like it or lump it, they have done
here) - cannot be succesful because the same substance can be made from chemicals which are everywhere - I may be able to legally indulge in amateur
chemistry again.
Sauron,
If people choose to take drugs, they choose the consequences of having done so - it's the old story - the devil said to man, 'take everything you want
- then pay for it', I don't see why other peoples choices should be paid for by me, however (and be that as it might) that is the situation here and
will be for the foreseeable future. In my opinion, if it can be shown that drugs can be manufactured via chemicals that no government is CAPABLE of
banning (whether because of logistical, financial or industrial pressure) then sooner or later they will face a choice. The sooner they face that
choice the better (ie. I can have my glassware again).
As to being a criminal, I rather believe that PROOF is required of an 'actual' offence, for which you need EVIDENCE. As far as I am aware, what I may
or may not personally believe is not a criminal offence (caveat, unless I support terrorism), nor is a theoretical discussion of basic chemistry. As
to whether drugs are harmful, of course they fucking are - they ARE poisons and if you wish to take them for any length of time you need your head
read. What I fail to understand is how they are any more harmful than alcohol or tobacco (given that they are less harmful by several orders of
magnitude). That being so, why shouldn't they be available in much the same way as both alcohol and tobacco - and why should such volumes of people be
imprisoned for their choice of drug?
Nicodem,
I appreciate your attitude to this aspect of our discussions, and reiterate, I have no intention of making ANYTHING illegal. That said, I regard (as
stated before) the war on drugs, from a slightly different perspective (ie. a legal one), although I personally (despite some personal experience,
which was long ago & which I survived) believe that drugs aren't good for you - this approach isn't going to fix the problem. The drugs aren't
going away and society is just going to have to adjust.
PS Why thank you, although I rather dislike the reference to Synthetikal, you did say that I sounded saner than they and with a better spell checking
facility (I don't use one).
As to everyone else, the War on drugs isn't going away - it serves way too many people, providing votes to politicians, jobs to police, lawyers and
judges, sales & ratings to the media. It also provides massive profits to people with no ethics and causes massive social problems. Unfortunately,
noone wants the thing to end, it is just so bountiful - despite destroying lives, jobs, etc. Whatever efforts are devoted to fighting it will be
wasted as the politicians will never say we need less laws and/or less police or whatever.
So where does that leave amateur chemistry here? In one word, fucked - if one chooses to own glassware at all in this place one is presumptively a
criminal, while virtually all accessible reagents and solvents are banned and a criminal offence to own or order. This is not going to change unless
the list of prohibited items becomes unworkable and unenforceable, which will be immediately the government attempts to prohibit either styrene or
acetic acid. As these cannot be prohibited and would quickly become the most often utilised reagents for meth cooks - of what use is the remainder of
the list in preventing the production of drugs? Therefore, of what utility is the list at all?![:D](./images/smilies/biggrin.gif)
So, once the list is of no relevance to whether or not the person is producing drugs, how then could police validly presume (as per the legislation)
that the owner of listed substances was producing drugs, because they owned something on the list? The answer is that they could not and due to the
illogical nature of the presumption it would be invalid - thus invalidating both the list and the presumption. Wham, I can own glassware and do stuff
again.
Not-important,
Finally back to the chemistry.... (Nicodem will be happy),
Ummm, yeah - thought that looked easy, the first patent does not depolymerize the polystyrene, it merely dissolves it. I did a quick patent search and
here is a recent patent regarding the depolymerization of styrene by heating the same to ~300C with an inert atmosphere (CO2) to prepare 99.5% pure
monomer:
http://www.freepatentsonline.com/6018085.html
Here is an older patent which shows that by first melting the polystyrene no solvent is needed (I don't know if this is accessible)
http://www.freepatentsonline.com/3901951.pdf
(I have attached this patent in PDF)
Their yield (without inert atmosphere) was up to 59% of starting polystyrene to styrene monomer.
I believe the original post referred to a gas phase process for the oxidation of styrene to styrene oxide (epoxide) and another gas phase reaction of
styrene oxide to phenylacetaldehyde (with silica gel - if not I have this from elsewhere).
If this is the intended use, I cannot see how the initial reaction could benefit from an inert atmosphere, as the oxidation of the styrene would be a
plus would it not?
tup
[Edited on 7-4-2007 by tupence_hapeny]
Attachment: Depolymerisation of Styrene (US Patent 3901951).pdf (160kB) This file has been downloaded 1426 times
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chemrox
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on the other hand .. re p2p
On the other hand:
Years ago I participated in an amphetamine synthesis contest and the whole point was to show that no matter what material you made unavailable there
were workarounds and ways to make methA. I suppose the same thing applies to p2p and showing that p2p can be made from so many different starting
points that making it illegal is absurd. There is something deeply wrong with US society and the speed epidemic is just a symptom. Furthermore
prohibition never worked. The DW is just another example. I say more power to those who publish methA syns and show it can be made from just about
anything. I don't understand the appeal myself.. but forcing manufacture into the hands of the cynical, desperate and unskilled is just making it
that more harmful to the people who are going to get it one way or another.
p2p was a cheap route to methA until it was proscribed. The ephedrine route was always known and available but with controls over p2p and one by one
the materials IT can be made from .. ad nauseum .. ephedrine ended up being te cheaper starting material bringing iodine and phospohorous under
scrutiny and finally making ephedrine virtually illegal. Now this really pisses me off .. I'm a diver and ephedrine is the agent of choice to quickly
clear sinuses for a period of three to six hours. So an easy way to make p2p is, in my view, a service to sportsmen and pilots as well as a blow to
the DW. All good things.
[Edited on 6-4-2007 by chemrox]
[Edited on 6-4-2007 by chemrox]
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roamingnome
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Method for recovering styrene monomer from polystyrene resin by using a catalyst
United States Patent 6380448
http://www.freepatentsonline.com/6380448.html
hydrated Epsom Salts are claimed to work
long ago ive come to the conclusion that opinions are meant for the fire
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tupence_hapeny
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Here is the patent for the production of phenylacetaldehyde from styrene oxide (epoxy), it uses the passage of gas phase styrene oxide through silica
gel (sorta explains the problem with isolating the yield experienced by so many researchers & also why the 'reactions' caused hydrolysis of the
product from the epoxidation):
http://www.freepatentsonline.com/4650908.html
As there is also a gas-phase oxidation of styrene, could this not all be run in one line?
depolymerization =(+ Heat & MgSO4)=> styrene =(Heat + supported silver catalyst)=> Styrene oxide =(silica gel)=> Phenylacetaldehyde
Here is the references regarding the vapor phase oxidation of styrene (the yields are ~50-75%, the remainder is unchanged styrene apparently):
http://www.freepatentsonline.com/5145968.html
http://www.freepatentsonline.com/4894467.html
[Edited on 7-4-2007 by tupence_hapeny]
Attachment: Production of Arylacetaldehydes (US Patent 4650908-1).pdf (125kB) This file has been downloaded 1435 times
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jim20/20
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Quote: | I still do not consider someone discussing how to make illegal drugs a criminal. His attitude certainly is hypocritical, but what is discussing about
making illegal drugs in comparison with discussing about making weapons of mass destruction? |
of course you are right nic
but neither is amateur chemistry
nor is political philosphy for that matter
'thou shalt oppose nor embarass those in power without being punished'
the hive is gone and the official line seems dubious
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not_important
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Quote: | Originally posted by tupence_hapeny...
As there is also a gas-phase oxidation of styrene, could this not all be run in one line?
depolymerization =(+ Heat & MgSO4)=> styrene =(Heat + supported silver catalyst)=> Styrene oxide =(silica gel)=> Phenylacetaldehyde
...
|
OK, here's some experience talking
First off, patents tend to omit minor details that would make it simple to replicate the process being described. Sometimes a patent is filed not
because the process was practical at the time, but as a protection in case someone else came up with a variant that could be economically useful. So
don't expect every patent to end up being useful to you.
The depolymerisation doesn't need a catalyst, try it plain and with a catalyst and compare the yields. The depolymerisation is aided by somewhat
reduced pressure, and by blue-to-UV light.
I've read lab reports that found that the presence of oxygen lead to the reforming of styrene polymers, properly oligomers which are formed even in
inert atmosphere but to a lesser extent - dealing with free radical processes here.
Because of the oligomers, as well as other decomposition products, it is worth fractionating the styrene. A Vigreux column was OK.
The conversion to the epoxide is a little tricky. BTW - not all the olefin is either unconverted or changed to epoxide, some ends up further oxidised
including being fully oxidised to CO2 and H2O. Too much air/oxygen can give an interesting blow torch effect inside the catalyst tube; it is rather a
bother to have a nice piece of heavy wall pyrex process tubing start to glow brightly and sag down, more so when this results in the tube's failure
and the flaming gases come rushing out. Do not try this in your kitchen or bathroom, don't try it in any room where soot covered walls are not
acceptable.
You need to get the proper amounts of oxygen to styrene, and the proper contact times for the temperature you are running at. Pressures a greater than
atmospheric and usually helpful, the patents even mention that.
Matching the rate of styrene production via destructive distillation to the need for tightly controlled O2/styrene rations and contact times (flow
rates) in forming the epoxide is not a simple chore. It's much easier to make the styrene, and use a vaporiser/mixer to get the right ratios and flow
rates. The problem is increased by the opposing pressure ranges favored by each process.
The epoxidation and and rearrangement are a closer match, but still perhaps not close enough. Experimentation will tell.
I went the epoxide route because I wanted b-phenylethanol too. It took more than a bit of tinkering to get it working. It still was more trouble than
using cold dilute permanganate to form the diol, and rearranging that with an acid catalyst.
As for going to the acid, Willgerodt using heavy walled pipe as an autoclave with an internal glass reaction vessel is a lot less work than going
through the aldehyde.
Of course I only wanted a couple of hundred grams of the acid, if you were going into manufacturing the air oxidation route would likely be better.
But why stop with the aldehyde? With some research you might be able to further oxidise the aldehyde, inject AcOH, and produce your desired product in
one vapour phase production stream. I'm sure that there are various ... notable figures who might be interested in financing such a research project.
However that might prove to be a little too interesting of a career choice.
While you're at it, do a search on the phrase "micro reactor" for a way that eases the path from research to macro quantities.
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Sauron
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@Nicodem, I have NEVER advocating making weapons of mass destruction on or off this board. To say I have done so is FALSE. I have discoursed on them,
and particularly on some of their precursors. So have many others. But I have also advised anyone who seemed in the slightest inclined to actually try
preparing them to abandon such plans.
@th on the other hand is an advocate of making illegal drugs, and is proposing that all of us do likewise as a supposed path to less restrictions on
our hobby. THAT absurdity is where I became disgusted with him and his rhetoric and not his (rather puerile) discussion of how to make P2P from PS
refuse.
I am not the only member to call bullshit on this guy, I see at least one moderator doing so although it is unclear whether or not he was acting in
his official capacity or privately.
I think any reasonably person would conclude from @th's remarks in this thread and one other, that he is as I concluded, a drug cook. I do not go
around the forum railing at anyone I think is a drug cook; but @th went far beynd the norm and cloaked his criminality in supposedly the holy cause
of defending Amateur Chemistry, which is just, IMO, a pose to hide his real intent just as pretending that utilizing polystyrene to make phenylacetone
is a pose. Else he might propose making polystyrene into something else, that is valuable and desirable and non-drug related, all in the name of the
Ozzie environment. But no, he settles on P2P.
P2P is a Sch 1 (I think) controlled substance now in USA. It is treated just as if it were heroin. It is not merely a listed precursor.
If we are in doubt as to @TH's status we can just ask him: are you making drugs or are you not?
If he answers honestly then at least he will have displayed some cojones.
If he says it is none of our business then we are eleft to draw our own conclusions.
I have already stated my own position relative to WMD's. I study them on PAPER. If someone wants to study illicit drugs on PAPER I do not care. If
someone makes them where they are legal I do not care (or at least I will keep my disapproval to myself.)
But, I say again, drug cooks and dealers are the roopt cause of our problems in amateur chemistry and a lot of larger problems in the world. Let's put
the blame where the blame belongs. It's long past time to abandon the armchair libertarianism and laissez-faire bullshit and realize that we are all
being made to suffer for the wrongdoings of a tiny minority of avaricious, greedy, arrogant criminals. We should not have ever tolerated them in our
midst and we should not do so now.
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Nicodem
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Quote: | Originally posted by tupence_hapeny
depolymerization =(+ Heat & MgSO4)=> styrene =(Heat + supported silver catalyst)=> Styrene oxide =(silica gel)=> Phenylacetaldehyde
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Letting industrial proceses aside, you might consider not to complicate things were not necessary:
1.) Styrene is a so called OTC compound. You can buy it pure of technical quality in specialized stores or reagent grade from a chemical supplier.
Both are extremely cheap. I see no point for something like a tedious distillation by destructive depolymerization that might end in explosions if
there is an air leak in the system.
2.) Styrene epoxidation is as simple a reaction as it can get. I have done it for fun in the times I was a bored amateur without any special equipment
(though you do need a distillation set and an aspirator). You can use completely OTC reagents, like trichloroisocyanuric acid or Oxone, both available
in their pure form in any larger store.
3.) The styrene oxide rearrangement can be performed in liquid phase, no need for tube furnaces and stuff like that. But if you just have to use a gas
phase reaction try to read this instead: Tetrahedron Letters, 29 (1988) 1471-1472.
4.) The epoxidation of styrene, the rearrangement, and oxidation to phenylacetic acid can be performed in a one-pot method using formic acid, aq. H2O2
and H2SO4. I tried this once and had a yield of 7% (actually, I did not even bother characterizing it, but it was a carboxylic acid and had the same
typical smell as reagent grade PhCH2COOH). I know what should be optimized for a better yield, but since I have no use for phenylacetic acid (and if I
had any use I would not need to prepare it) I never tried to do any better than that. The aldehyde to carboxylic acid oxidation reaction is described
in Synthesis, (1993) 295-297 while the first two reaction steps are trivial and there is no particular limitation for a one-pot process.
5.) Like not_important said, the Willgerodt reaction followed by hydrolysis is way more rational than your multistep proposal unless you have some
industry to do the work for you. Besides all this styrene stuff was already discussed add nauseam in other threads, the most useful for you would be
this one. But do UTFSE by yourself!
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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tupence_hapeny
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Nicodem,
I have intentionally gone a different way to the Wilgerodt-Kindler reaction, simply because I have a marked aversion to playing with hydrogen sulfide
(H2S) and do not believe that this reaction is SAFE in the hands of either an
amateur chemist or a ‘meth’ cook (which I note that I am still being called). Quite simply, the capacity for this gas to be released in some
quantity is dangerous not only to the person using the reaction, but also to persons in the immediate area of
the same. Another factor is the emissions, which is the primary reason why industry does not use this.
Yes, styrene monomer is widely available – albeit in an impure form – although I would suggest that the same is easily banned (or made available
only under license), whereas polystyrene cannot be banned effectively.
Finally, I have noticed numerous threads on this topic, the conversion of the polymer to the monomer, then to the aldehyde, etc. For the most part
such threads are silent on detail and specifics, I believe that it is time to ‘put up or shut up’ if you will, and examine the specific reactions
and the mechanics of the conversions in order to ascertain whether this is, or is not, a viable source of the desired compound(s). Perhaps even
exploding some popular myths on the way.
Not_important,
As stated above, I am trying to dodge the Wilgerodt-Kindler style reaction, due to the level of byproducts which must be dealt with (although, and as
a recurring theme, could NMP [as a high-boiling amine] be used instead of pyridine or morpholine?). I am interested in your experiences with this
specific type of reaction, although I am interested to know the role of the ‘blue-light’ in the sequence (as no mention is made in any of the
patents of such)?
As to the reactions, the epoxidation requires oxygen and an inert gas, would carbon dioxide suffice (as this would already be in the mix and moreover
is given off by the reactions). That would mean that oxygen could be added at a predetermined rate (based on the flow from the styrene
depolymerization reactor) along with some steam in the final step.
Alternatively, bearing in mind that the object is to provide a workable synthesis, could a minor amount of oxygen be added to the carbon dioxide
during the styrene depolymerisation? This would cut down on unwanted side-reactions, while providing the oxygen for the next step – thus needing
only additional heat in order to complete the epoxidation step.
Back to the chemistry,
The phenylacetaldehyde coming from the reaction tube is of course going to be accompanied by unreacted styrene, three xylenes, and assorted dimers and
trimers (and tetramers), although (and providing the reactions work as advertised) these should be mainly styrene. I am unaware if either styrene or
xylene would react with acetic acid/acetone, if they will it will be necessary to remove them, if not, do it at the end. Personally I would prefer
purification at this stage.
Making the Ketone
There are three major routes:
(1) reaction between phenylacetic acid and acetic acid;
http://www.orgsyn.org/orgsyn/prep.asp?prep=cv2p0389
(2) reaction between phenylacetic acid and acetone; &
http://www.freepatentsonline.com/4528400.html
http://www.freepatentsonline.com/4570021.html
(NB these patents actually claims to be useful in making BMK)
(3) reaction between phenylacetaldehyde and acetic acid
http://www.freepatentsonline.com/6495696.html
http://www.freepatentsonline.com/6392099.html
Given that phenylacetaldehyde reacts with acetic acid to give the desired ketone (the patent is for cyclopropylketone) and phenylacetic acid reacts
with acetone to give the desired ketone, wouldn’t a fourth variant be at least theoretically possible? Being the reaction between phenylacetaldehyde
and acetone? (If not, I have patents for the production of acetic acid from ethanol in the gas phase).
However, if the phenylacetaldehyde cannot be used directly, I am yet to find a mechanism for the conversion of the same to the acid – except in the
liquid phase reaction with nickel peroxide (nickel oxide hydroxide [thanks Sauron]).
Sauron,
Sir, I note your continued strident remarks and wish to state unambiguously and categorically, that I do NOT NEED to make drugs and reiterate my
statement that I have no intention of doing so. That being said, the development of industrial routes to compounds that are listed, using none of the
compounds that are listed – purely to prevent the making of the first – is a matter of serious, professional interest.
The synthetic route under discussion is, of design, an industrial style process – knowledge of the mechanics of which may be extremely useful to
myself (and potentially my client) in some, as yet to arise, situation or occasion. It will however be necessary to establish that such a route is
within the limited knowledge of chemistry that is presumed to be within the grasp of the average, or slightly above average, ‘cook’, thus the
emphasis upon simplicity and ease of operation. Additionally, if actual ‘criminals’ use this information to make drugs and get busted, their
actions will only advance my argument, given that the information from their trial will be admissible in other trials to demonstrate the validity of
the route.
Cold blooded enough for you Sir?
tup
[Edited on 7-4-2007 by tupence_hapeny]
We are all the sum of our experiences, and our reactions to the same
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Sandmeyer
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Quote: | Originally posted by Nicodem
Though I do not like Tupence, mainly because he sounds like Synthetikal on medication and with a spell checker and find his apologetical ideology
disgusting |
I think all of them, including "Sauron" (our "retired defense consultant") sound more or less the same, maybe all these personalities co-exist in the
same body. It must be the madness part of sciencemadness that attract all those crazies..
![:D](./images/smilies/biggrin.gif)
[Edited on 7-4-2007 by Sandmeyer]
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Sauron
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@sandmeyer's comment is sufficiently asinine to require no additional comment from me. Did he actually mean ti suggest that I am @th?
What an insult!
And no need for quote marks about retired defense consultant, @sandmeyer, I AM a retired defense consultant. And a senior defense-intelligence
journalist as a result. It so happens that on the MadHatter ftp site there is a book with an entire chapter devoted to me and my work and my photos
grace the cover of that book and the chapter. So, take your little puerile sneer and go fuck yourself with it.
(You see, gentlemen and ladies, I have been the victim of @Sandmeyer's poison pen before and I am not about to accept any more abuse from him.)
[Edited on 7-4-2007 by Sauron]
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tupence_hapeny
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I can't think why...
We are all the sum of our experiences, and our reactions to the same
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