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Swinfi2
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Acid Chlorides
(Excuse me if my searching was bad but I didn't find anything on the topic)
Has anyone found the need for acid chlorides? Specifically a way to make them avoiding "schedule 3 chemical weapons" as my best idea so far is:
red P and chlorine -> PCl3
PCl3 + organic acid -> acid chloride
Purely a thought experiment at this stage, PCl3 is way above my safety/equipment capacity right now so equilibriums will have to do, but still they
might be useful if there is a safer (or of less questionable legality) method out there?
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Magpie
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RCOOH + SOCl2 → RCOCl + SO2 + HCl
SOCl2, thionyl chloride, can be made at home, with much labor. See my "preparation of thionyl chloride," this forum. But SOCl2 is a "3B chemical
weapons" precursor. But, then again, so is PCl3. http://www.australiagroup.net/en/precursors.html
I don't think there is a cheap and easy way to make acid chlorides if that is what you are asking. If it was many here would be doing same. It is
easier to make phosphorus.
[Edited on 21-2-2018 by Magpie]
The single most important condition for a successful synthesis is good mixing - Nicodem
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JJay
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There is a way that has not received much attention in the scientific literature that involves mixing the carboxylic acid with acetonitrile under
anhydrous conditions and gassing it with hydrogen chloride. Chem Player tried it and says it works for acetic acid. There's a thread on it around here
somewhere....
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Chemi Pharma
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The video Chem Player did about making acetyl chloride from acetonitrile, acetic acid and gaseous HCl can be find here:
https://www.youtube.com/watch?v=ExDI9KUW-9Q
But this synthesis suffers from low yields, as you can see in the video.
Exist a better way to make acid chlorides with satisfactory yield, without the use of dangerous POCl3, PCl3, PCl5 or thionyl choride, using OTC
Cyanuric chloride, carboxilic acid in acetone and TEA (triethylamine) with stirring at room temperature, like said in the paper attached:
Attachment: Acetyl chloride and Benzoyl chloride from Cyanuric Chloride & Carboxylic Acids.pdf (86kB) This file has been downloaded 858 times
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Magpie
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Where do you find cyanuric chloride OTC?
The single most important condition for a successful synthesis is good mixing - Nicodem
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woelen
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Many people make the mistake of thinking that cyanuric chloride is the same as trichloroisocyanurate (TCCA). They are not the same. Cyanuric chloride
is C3N3Cl3, while TCCA is C3N3Cl3O3. The latter is available OTC as swimming pool chlorinator. Their molecular structures are somewhat similar, both
contain an alternating N-C ring with 6 atoms, adding to the confusion.
TCCA reacts slowly with water to form HOCl and cyanuric acid. Cyanuric chloride reacts with water to form cyanuric acid and hydrochloric acid.
TCCA is strongly oxidizing and certainly will not be useful for replacing hydroxyl groups with chlorine atoms in organic compounds, such as alcohols
and carboxylic acids. With many organic compounds, TCCA will react very violently and strongly exothermically. Be careful when mixing that with
organics!
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Chemi Pharma
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Sorry if it's not OTC where you live @magpie. I really don't know about it's situation world wide, but here in latin america you can find it at every
chemical vendor relatively cheap. For example, I bought mine (1 kg) paying U$120,00 at a local vendor. No hard to get at all, at least here.
Cyanuric chloride it's a very useful and versatile reagent. The researchers are discovering more and more uses for it at organic chemistry nowadays. I
have many papers about what you can do with it. Worth it a try to buy and do some experimentation.
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Chemi Pharma
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Quote: Originally posted by woelen | Many people make the mistake of thinking that cyanuric chloride is the same as trichloroisocyanurate (TCCA). They are not the same. Cyanuric chloride
is C3N3Cl3, while TCCA is C3N3Cl3O3. The latter is available OTC as swimming pool chlorinator. Their molecular structures are somewhat similar, both
contain an alternating N-C ring with 6 atoms, adding to the confusion.
TCCA reacts slowly with water to form HOCl and cyanuric acid. Cyanuric chloride reacts with water to form cyanuric acid and hydrochloric acid.
TCCA is strongly oxidizing and certainly will not be useful for replacing hydroxyl groups with chlorine atoms in organic compounds, such as alcohols
and carboxylic acids. With many organic compounds, TCCA will react very violently and strongly exothermically. Be careful when mixing that with
organics! |
@Woelen is right. Many people make a mistake thinking TCCA is the same of Cianuric Chloride. TCCA is a oxidanting agent and cyanuric chloride is a
chlorinating agent, though TCCA can act sometimes as a chlorinating agent too.
Cyanuric chloride is the trimmer of cianogen chloride (CNCl) and a very useful and versatile reagent in organic chemistry.
Thinking better, @magpie is right. It's not so OTC than TCCA at all.
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byko3y
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Cyanuric chloride is not even close to OTC and can be obtained only from specialized chemical distributors or some secondary market (later is risky
due to usually short shelf life).
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Swinfi2
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I've just found this (http://www.sciencemadness.org/talk/viewthread.php?tid=27073) about cyanuric bromide, seems like a "safer" alternative as RT gases are avoided but
it doesn't look the easiest to make. Looks like acyl halides are a ways off for me at least.
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clearly_not_atara
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The acetonitrile method deserves further consideration. A paper I dug up earlier shows that acetonitrile dimerizes in the presence of HCl to form
1-(1-chlorovinyl)-1-aza-2-aminopropene, which appears (structurally) to be a more active chlorinating agent than acetonitrile. This means that two
equivalents of MeCN react with one equivalent of carboxylic acid, which explains to some extent the low yields.
Anyway HCl gassing is much safer than any other method, including the bromine bomb I posted about years ago.
EDIT: Original post, and picture:
https://www.sciencemadness.org/whisper/viewthread.php?tid=9&...
[Edited on 21-2-2018 by clearly_not_atara]
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Mothman
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Could one potentially reduce the TCCA using carbon powder or would that wind up releasing a ton of dangerous crap like cyanogen chloride and phosgene?
You can be happy
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Chemi Pharma
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I found that Liebig have synthesized and discovered cyanuric chloride in 1827, by passing chlorine into a flask with dry potassium thiocyanate, what
seems not too difficult. However, I found nowhere on the NET this synthesis in details. If anybody here could get it and post here, it will be much
appreciated.
The industrial way to make it reacting Chlorine with HCN is far from what can be made by an amateur chemist without risk of death.
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Melgar
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Benzotrichloride seems easier to make than a lot of your suggestions, however you'd need about twice as much chlorine gas as you'd need to make
phosphorus trichloride.
Phosphorus halides are the easiest way to go. Bromides and chlorides are close enough in reactivity that they're essentially interchangeable. And
phosphorus isn't actually illegal to own as long as your plans for it don't include making methamphetamine.
The first step in the process of learning something is admitting that you don't know it already.
I'm givin' the spam shields max power at full warp, but they just dinna have the power! We're gonna have to evacuate to new forum software!
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clearly_not_atara
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On the subject of benzotrichloride, benzoyl chlorides can be formed by chlorination of benzaldehydes. A chlorination of m-chlorobenzaldehyde is given
in Organic Syntheses as part of the leadup to mCPBA. These are a little easier to handle than benzotrichloride.
Quote: Originally posted by Mothman | Could one potentially reduce the TCCA using carbon powder or would that wind up releasing a ton of dangerous crap like cyanogen chloride and phosgene?
| No; it will decompose, perhaps violently. The problem with any reduction is that in TCCA, Cl is bonded to N
(a weak, thus dangerous, bond) whereas in TCT, Cl is bonded to C. Reduction cannot rearrange this bond, certainly not in a crude dry-distillation
setup.
[Edited on 21-2-2018 by clearly_not_atara]
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AvBaeyer
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Acid chlorides can be prepared using TCCA and triphenylphosphine. There are several publications that deal with this some of which I have attached.
Triphenylphosphine is readily available from internet sources and is not controlled or watched.
I have made some acid chlorides using these reagents and they work well. The draw backs are that the reactions can get out of control (typical of
TCCA) and of course a lot of relatively useless triphenylphosphine oxide is produced.
Another very mild and convenient way to activate acids for amide and ester formation and other useful chemistry is with carbonyldiimidazole. This
reagent is also easily available and though somewhat pricey is really a great one to use. If anyone is interested I can provide some references.
I hope these help.
AvB
Attachment: SynComm1999_29_1415 TCCA-TPP.pdf (172kB) This file has been downloaded 624 times
Attachment: TetLet2005_46_5945 TCCA-TPP.pdf (105kB) This file has been downloaded 871 times
Attachment: Aldehydes to Acid Chlorides w TCCA FR2633616A1.pdf (199kB) This file has been downloaded 632 times
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Melgar
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Oh, if benzotrichloride is too annoying for you to work with, it can actually tun benzoic acid into benzoyl chloride, forming benzoyl chloride itself.
Benzoyl chloride is good for making low-boiling point acyl chlorides, and apparently less frustrating to work with.
The first step in the process of learning something is admitting that you don't know it already.
I'm givin' the spam shields max power at full warp, but they just dinna have the power! We're gonna have to evacuate to new forum software!
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Chemi Pharma
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Thanks @AVBayer for the papers. Very instructive. I had only a paper dealing with alcohols alkylations with the mix TCCA/Triphenylphosphine in
acetonitrile, atached below.
I didn't know the couple TCCA/triphenylphosphine can acts the same way cyanuric chloride alone in acylation or amidation of carboxilic acids, making
nitriles from amides and to make vinyl chlorides from 1,3 diketones.
Glad to know about this other OTC route.
Attachment: Alcohols to Alkyl Chlorides with TCCA and Triphenylphosphine.doc (45kB) This file has been downloaded 607 times
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Boffis
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Thanks guys for these papers, some very interesting and useful chemistry.
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FireLion3
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Quote: Originally posted by Chemi Pharma |
Sorry if it's not OTC where you live @magpie. I really don't know about it's situation world wide, but here in latin america you can find it at every
chemical vendor relatively cheap. For example, I bought mine (1 kg) paying U$120,00 at a local vendor. No hard to get at all, at least here.
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I think there is slight confusion about the term OTC. In the US, Cyanuric Chloride is readily available at many chemical vendors and online chemical
stores, but such stores are not what people think of when they say OTC. I think when most people say OTC, they mean readily available at big box
stores that most people can drive to in a few minutes of their house and grab off the shelf, rather than specialized chemical companies.
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woelen
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My idea of OTC vs. not OTC at all:
- TCCA can be purchased at many gardening stores, swimming pool stores and also several hardware stores. No questions asked, just pick a bottle from
the shelve, pay and drive away.
- Chlorocyanuric acid can be purchased where I live, but only from a few online chemical suppliers, catering to private individuals and only after
filling in a declaration of use form with corresponding ID.
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Chemi Pharma
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Quote: Originally posted by woelen | My idea of OTC vs. not OTC at all:
- TCCA can be purchased at many gardening stores, swimming pool stores and also several hardware stores. No questions asked, just pick a bottle from
the shelve, pay and drive away.
- Chlorocyanuric acid can be purchased where I live, but only from a few online chemical suppliers, catering to private individuals and only after
filling in a declaration of use form with corresponding ID.
|
umh, now I understand the cause of the misunderstood. In my concept, I've thought OTC is the reagent you can find and purchase even at a chemical
supplier, internet sites like alibaba, ebay, Mercado Livre (here at Brazil), flagrancy stores, or any kind of stores, buying the good as a private
individual, withouth filling any paper, no control by authorities and sent to you by mail post or got personally at a store, and NOT OTC is those
reagents hard to find at even chemical vendors, sold only to companies, that have some kind of restriction to buy, or even watched by the authorities,
that is, those reagents you need someone in the middle to get if for you, paying much more than the real price.
I believe my concept was wrong until now, reading what you've posted guys. I apologize and tell you that I will not use the term OTC here in the forum
anymore, to don't cause more confusions. I will only use the terms "easy or hard to find or purchase" and "watched or not watched".
[Edited on 23-2-2018 by Chemi Pharma]
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clearly_not_atara
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Triphenylphosphine is also not OTC, as far as I'm aware. It's not interesting to the fuzz, though.
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Chemi Pharma
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May be, but as TCCA, is easier to purchase than POCl3, PCl3, PCl5 or SOCl2, cited here like an easy option to acylate carboxilic acids, which does not
correspond to the truth.
If I have a good synthesis, with high yielding, using easy to purchase chemicals, like cyanuric chloride or TCCA/Triphenilphosphine couple, why do I
need to use these hard to get an watched chemicals? All of them are chemical weapons precursors. Even try to make them in a home lab is a pain in the
ass. Dealing with chlorine, phosphorous and SO3 is not for beginners.
[Edited on 23-2-2018 by Chemi Pharma]
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FireLion3
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Quote: Originally posted by Chemi Pharma |
umh, now I understand the cause of the misunderstood. In my concept, I've thought OTC is the reagent you can find and purchase even at a chemical
supplier, internet sites like alibaba, ebay, Mercado Livre (here at Brazil), flagrancy stores, or any kind of stores, buying the good as a private
individual, withouth filling any paper, no control by authorities and sent to you by mail post or got personally at a store, and NOT OTC is those
reagents hard to find at even chemical vendors, sold only to companies, that have some kind of restriction to buy, or even watched by the authorities,
that is, those reagents you need someone in the middle to get if for you, paying much more than the real price.
I believe my concept was wrong until now, reading what you've posted guys. I apologize and tell you that I will not use the term OTC here in the forum
anymore, to don't cause more confusions. I will only use the terms "easy or hard to find or purchase" and "watched or not watched".
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There's no need to apologize; it was a harmless confusion. Usually if a chemical is only available at chemical suppliers, people will just say that it
is "Commercially Available", meaning not (usually) requiring any special licensing and permits and so on. If something isn't commercially available,
then that usually means it is very rare, hard to find, or must be special orders on a custom-synthesis basis.
You said you were in Latin America? Are the regulations strict there? In the US there's not that many chemicals that require filling out a bunch of
paperwork to get, unless someone is trying to purchase known precursor chemicals, or purchasing ridiculous quantities of watched chemicals. For the
most part the US chemical market is pretty open. At least in my opinion. I know other countries out there are far more regulated, especially in
Europe.
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