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Author: Subject: chloral hydrate synthesis
MagicJigPipe
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[*] posted on 22-9-2007 at 14:22


What about the sodium hypochlorite and NaOH that was probably produced in that reaction because of the water content of the liquor. There would have to at least be some left in there. That can't be good for you.
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[*] posted on 22-9-2007 at 20:08


What water content?

Ethanol. ANHYDROUS ethanol. Did you bother to read the references?

You were maybe planning to chlorinate vodka?
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[*] posted on 22-9-2007 at 22:55


The only post that refers to using LIQUOR.

"Some bacardi 151 proof rum [yellowish tint] was poured into a beaker along with more than enough iodized table that would disolve in it. "

[Edited on 9-23-2007 by Polverone]
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[*] posted on 22-9-2007 at 23:13


Oh, I DO see some rather stupidposts by a guy named punk quite appropriately, BACK ON PAGE 1. THIS IS PAGE 3.

If you insist on replying to ancient posts the standard practice is to use the Quotes key so that members will see what you are referring to.

[Edited on 9-23-2007 by Polverone]
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[*] posted on 16-6-2008 at 00:27


US2443183 may be of interest to those interested in ethanol chlorination.
BTW it mentions the danger of explosions, which I'd not seen explicitly mentioned before.
It is related to US2478152, both by O.W. Cass for DuPont.

[Edited on 16-6-2008 by S.C. Wack]
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[*] posted on 22-6-2008 at 13:14


Quote:
Originally posted by S.C. Wack
US2443183 may be of interest to those interested in ethanol chlorination.
BTW it mentions the danger of explosions, which I'd not seen explicitly mentioned before.
It is related to US2478152, both by O.W. Cass for DuPont.

[Edited on 16-6-2008 by S.C. Wack]


I scanned this entire thread to see if anyone posted these patent refs. Way to go, Wack!

The usual procedure in chemical research is to first define the task or problem, then check ALL of the original source literature BEFORE starting any lab work. The saying goes: A day in the library is worth a week in the laboratory. The case of chloral hydrate raises an additional caveat: oxidizing absolute EtOH with chlorine can lead to fires & explosions. Spending the time required to check the background lit sure beats having to explain what you were up to in your home lab to the policeman & fire chief after they put your house fire out!

In general, I would never take something found on the Web & trust it as being accurate without checking the literature first. Mistakes get made, things that are wrong get repeated, things get left out. Webmasters at rhodium & erowid are not necessarily trained chemists or trained transcribers. And there are even errors in the literature, which is why you have to check as many references as you can before you start working with chemicals.

Since few of us have ready access to back issues to journal articles, a handy (as in free) reference database is in patents. A great tool is the new search engine by Google found at http://www.google.com/advanced_patent_search. They did an OCR scan of the entire U.S. Patent database and you can search it by key word, as in 'chloral hydrate.' The DuPont patents referenced above show up in the first page of results. But be careful: their database is not complete & the OCR process garbled a lot of names & words, so no search in this database is going to be even close to 100%. But at least it's a start.

For patents issued after 1976, the USPTO search interface at http://www.uspto.gov/patft/index.html is more thorough but it would miss the DuPont patents because they issued prior to 1976. You do need a TIFF viewer (free download) to see the patents in full image. To search patents prior to 1976 you have to search by patent Class, which can get very confusing & very time-consuming even for trained chemists/patent lawyers. For example, the DuPont US2478152 can be found in the following patent Classes: 204/157.9 ; 204/157.93; 568/487; 568/488; 568/599; 568/676

[Edited on 22-6-2008 by Ritter]




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[*] posted on 22-6-2008 at 13:55


When I was a student sometime after the Big Bang and before recorded history, it was pounded into me not to place too much faith in chemical patents. This is not to say ignore them; just don't take them at face value.

A half century in organic chemistry has done nothing to erode that pedagogy. Neither has extensive experience with patent lawyers, the application drafting process and prosecution of such application.

The chemical literature, particularly that of the last and present centuries, is terra firma. The rest is all too often a quagmire.




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[*] posted on 23-6-2008 at 05:18


Quote:
Originally posted by Sauron
When I was a student sometime after the Big Bang and before recorded history, it was pounded into me not to place too much faith in chemical patents. This is not to say ignore them; just don't take them at face value.

A half century in organic chemistry has done nothing to erode that pedagogy. Neither has extensive experience with patent lawyers, the application drafting process and prosecution of such application.

The chemical literature, particularly that of the last and present centuries, is terra firma. The rest is all too often a quagmire.


My point was that few here have ready access to the original journal articles but instead have free access to the patents. They are a major improvement over relying instead on syntheses found on clandestine drug web sites.

[Edited on 23-6-2008 by Ritter]

[Edited on 23-6-2008 by Ritter]




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[*] posted on 23-6-2008 at 05:57


Ritter, please be advised that many or most of us here do have access to a great many major primary journal archives. Some online, some on the ftp servers associated with the forum, some downloaded onto CD or DVD or HDD so that we don't have to go online at all in many instances. I have most of the Beilstein Hauptwerk in pdf for example, and quite a bit of Houben-Weyl, not to mention several editions of Merck, Ullmann's, Kirk-Othmer - all secondary lit. to be sure, but I also have many complete journal sets.

I can tell you that all of Chem.Ber. prior to 1902 is available free online. After that, from Wiley and some of us have access and share with each other. Ditto J.Prakt.Chem., Liebig's Annalen, Cptes Rend, etc.

And books, hundreds of gigabytes of organic chemistry books.

Sure the patent lit. has its place. But I recommend you get the PW for References, and have someone explain to you how to get onto the various ftp servers. I hope you have a lot of disk space. You will need it!




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[*] posted on 23-6-2008 at 06:35


Quote:
Originally posted by Sauron
Ritter, please be advised that many or most of us here do have access to a great many major primary journal archives. Some online, some on the ftp servers associated with the forum, some downloaded onto CD or DVD or HDD so that we don't have to go online at all in many instances. I have most of the Beilstein Hauptwerk in pdf for example, and quite a bit of Houben-Weyl, not to mention several editions of Merck, Ullmann's, Kirk-Othmer - all secondary lit. to be sure, but I also have many complete journal sets.

I can tell you that all of Chem.Ber. prior to 1902 is available free online. After that, from Wiley and some of us have access and share with each other. Ditto J.Prakt.Chem., Liebig's Annalen, Cptes Rend, etc.

And books, hundreds of gigabytes of organic chemistry books.

Sure the patent lit. has its place. But I recommend you get the PW for References, and have someone explain to you how to get onto the various ftp servers. I hope you have a lot of disk space. You will need it!


So you made my point: there can be no excuse for not performing an adequate literature search before starting a new synthesis project.




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[*] posted on 23-6-2008 at 08:18


That point was never in dispute as far as I am concerned.

Though in the case at hand I am skeptical about any explosion hazard in the chlorination of ethanol, a reaction that has been scrutinized for 180 years. Certainly none on the bench scale.




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[*] posted on 23-6-2008 at 08:57


I think that the chance of an explosion is remote but possible.
The first step in the formation of chloral hydrate is the reaction of chlorine and ethanol to form ethyl hypochlorite.
This then breaks down to form ethanal ( probably via a radical mechanism ) and hydrogen chloride.
Accumulation of ethyl hypochlorite in the reaction mixture or overheating in the early stages could cause the ethyl hypochlorite to explode.
Protonation / deprotonation of the ethanal then yields the enol which undergoes electrophilic attack by chlorine.
Raising the temperature is required as the substitutions proceed as the mono and di substituted aldehydes are more resistant to reaction.
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[*] posted on 23-6-2008 at 10:15


Quote:
Originally posted by ScienceSquirrel
I think that the chance of an explosion is remote but possible.
The first step in the formation of chloral hydrate is the reaction of chlorine and ethanol to form ethyl hypochlorite.
This then breaks down to form ethanal ( probably via a radical mechanism ) and hydrogen chloride.
Accumulation of ethyl hypochlorite in the reaction mixture or overheating in the early stages could cause the ethyl hypochlorite to explode.
Protonation / deprotonation of the ethanal then yields the enol which undergoes electrophilic attack by chlorine.
Raising the temperature is required as the substitutions proceed as the mono and di substituted aldehydes are more resistant to reaction.


DuPont has a big thing about safety. They would not have mentioned that in the patent if it weren't a real possibility. Absolute EtOH is extremely flammable & a lot of energy is getting released in the chlorine oxidation.

[Edited on 23-6-2008 by Ritter]




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[*] posted on 23-6-2008 at 19:13


The literature of chloral is huge. It spans almost two centuries, and has been thoroughly reviewed in recent time. The patent literature continues well into the second half of the 20th century. Yet this mention in a single patent is apparently the only time that mention has been made of any such explosion hazard.

Of course EtOH is flammable. That does not mean distilleries burn down every week.

The normal procedure is to chlorinate not quite anhydrous ethanol (read the review of chloral I posted elsewhere) at 0-20 C until a certain mass gain and density are chieved and then to increase the chlorine flow, the heat of reaction will raise the pot temperature until reflux.

If anyone is concerned about chlorination of ethanol, you can just chlorinate acetaldehyde this skipping the whole ethyl hypochlorite phase.

As for flammability, try chlorinating CS2 sometime.




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[*] posted on 24-6-2008 at 17:12


It's said that ethyl hypochlorite can detonate if superheated, in the presence of copper powder or in bright sunlight :o An earlier review of the chemistry of choral and chloral hydrate was published by Hirwe in the Journal of the University of Bombay 6 Pt II, 182-198 (1937) :D Chloral has been used to dry halogenated fire extinguishing compounds :cool:

Attachment: DE554521C1.pdf (130kB)
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[*] posted on 24-6-2008 at 17:31


Quote:
Originally posted by Sauron

Of course EtOH is flammable. That does not mean distilleries burn down every week.



Distilleries are not using a powerful oxidizing agent such as chlorine.




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[*] posted on 24-6-2008 at 18:20


Prudence is one thing. Paranoia and fear-mongering is quite another.

The patent mentions a remote possibility in context of an industrial scale chlorination of ethanol, the province of process C.E.s.

I would characterize the remoteness of the hazard in a bench scale chlorination of ethanol, conducted competently, as extreme. Extremely remote. Surely the essential absence of such hazard in the voluminous literature of chloral, supports my estimate.

In short it was simply not a very good example of the sort of detail to be unearthed in a prudent search of the lit.

I conducted a prudent search of the lit. on chloral and I intend to make chloral, for purpose of converting to CCl4. If I blow myself up, feel free to say "I told you so" as much as you like. :)




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[*] posted on 29-6-2008 at 19:10


ok can someone please give me/us a simple step by step procedure to making chloral hydrate. i can easily get 95% pure ethanol aka everclear/goldengrain. thats not an issue. just give me some simple step by step directions, i dont care for why this happens or the reactions and wut this means. just what to do, what happens, and then what else to do, etc. till finish.

like:'

1) mix this with this

2) heat this with that

3) do this

4) mix that here let it sit for a few days

5) mix this heat that

6) filter this

simple pls. and there may be fancy shmancy ways out there to make this stuff but i need a method that uses the simplest easiest to get chemicals. if something isnt easy to get then give me an easy way to cook it up myself.

[Edited on 29-6-2008 by mrmz88]
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[*] posted on 29-6-2008 at 19:47


Quote:
Originally posted by mrmz88
ok can someone please give me/us a simple step by step procedure to making chloral hydrate. i can easily get 95% pure ethanol aka everclear/goldengrain. thats not an issue. just give me some simple step by step directions, i dont care for why this happens or the reactions and wut this means. just what to do, what happens, and then what else to do, etc. till finish.

like:'

1) mix this with this

2) heat this with that

3) do this

4) mix that here let it sit for a few days

5) mix this heat that

6) filter this

simple pls. and there may be fancy shmancy ways out there to make this stuff but i need a method that uses the simplest easiest to get chemicals. if something isnt easy to get then give me an easy way to cook it up myself.

[Edited on 29-6-2008 by mrmz88]




Absolutely not. Stop asking for blatant spoonfeeding and take your cookery elsewhere. First of all, this is a relatively simple concept. If you can't even take the time to read the thread and figure it out, I wouldn't trust you with a wooden cooking spoon, much less the necessary chlorine gas.

If the mods want to snip this post out along with the drek above it, go ahead.

[Edited on 6-29-08 by UnintentionalChaos]




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[*] posted on 29-6-2008 at 20:20


There's an excellent review of chloral chemistry from Chem.Rev. which I posted here some time back, perhaps in this very thread. If you read the thread perhaps you will find it. Early on the review described this preparation, which is rather simple.



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[*] posted on 29-6-2008 at 21:47


Quote:
Absolutely not. Stop asking for blatant spoonfeeding and take your cookery elsewhere. First of all, this is a relatively simple concept. If you can't even take the time to read the thread and figure it out, I wouldn't trust you with a wooden cooking spoon, much less the necessary chlorine gas.

If the mods want to snip this post out along with the drek above it, go ahead.

[Edited on 6-29-08 by UnintentionalChaos]


why? ur afraid ill asplode someones house up? well i probably will trying to figure out all this crap i dont care about. just give me simple directions and then i wont have to look up stuff and get confused and then nothing will blow up.

Quote:
There's an excellent review of chloral chemistry from Chem.Rev. which I posted here some time back, perhaps in this very thread. If you read the thread perhaps you will find it. Early on the review described this preparation, which is rather simple.


u said "its on page 15 in references" but i dunno how to get in and it says u need permission from moderator or something

[Edited on 29-6-2008 by mrmz88]

[Edited on 29-6-2008 by mrmz88]
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[*] posted on 29-6-2008 at 22:12


Judging from your intentions you do not need to be working with Cl2. Nobody is going to willingly do what you are asking so just stop. There are other sites that better suit your needs. I don't think I can mention them here but, you can figure it out. I think...

And it's not about "asploding" anything. It's about gassing yourself with chlorine or getting caught doing this and damaging the reputation of home chemistry which is very likely judging solely from the quality of your posts. No offense. Really. (but I sure hope "88" isn't your birth year). In that case it is my opinion that you are too old to be spoonfed. Get a knife and fork and chew your own food! *pathetic attempt at a "metaphor"/"analogy"*

[Edited on 6-30-2008 by MagicJigPipe]




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[*] posted on 4-7-2008 at 21:28


Hey I'm young (my birth year is '84), but people like this are what give amateur chemists a bad name! More than half the time I'm more interested in the mechanisms of a reaction (mainly organic chem) than the final product itself! Long time lurker, first time poster by the way. Anyways, take the time to know what you're doing before you do it! You may just learn something, :-D
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[*] posted on 4-7-2008 at 22:19


Quote:
but i dunno how to get in and it says u need permission from moderator or something


A good way to get that is to contribute to the discussions in a constructive way, using conventional language. Asking for recipes is generally frowned on here as the emphasis is on learning why as much as how.

Or you can learn how to use search engines and track down the old, out of copyright books that have descriptive preparation methods in them, download them, and go from there.
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[*] posted on 26-10-2010 at 15:06


Quote: Originally posted by guy  
I am playing around with making chloral hydrate.

I am adding NaDCCA to a solution of Ethanol and 29% HCl. When I did this reaction (outside) late in the evening, I noticed it proceeded fairly slowly and the green color lasted for about 20 minutes before it faded and the reaction temperature did not change that much.

Today I did it in the afternoon with strong sunlight and the green color of chlorine was removed almost instantaneously and the reaction mixture got quite hot. This indicates that Cl2 is being broken into radicals and reacting with the ethanol or acetaldehyde. Cl2 breaks up at 493 nm so this seems quite plausible.


I've read through this thread, and as far as I can see, there have been mentioned only two experimantal attempts at chloral or its hydrate:

1. chlorination of ethanol by bubbling chlorine through (cooled) ethanol;
2. the method quoted above.

This experiment is interesting as it gives experimental evidence of the influence of light on the speed of at least the intial chlorination step. I'm willing to take on an experimental attempt to produce chloralhydrate, but not if it requires bubbling chlorine for hours. My question is: what does DCCA stand for?

------------------------------

Since it is my aim to produce trichloroacetate, not chloralhydrate, does anyone know of an easy procedure to chlorinate acetic acid or an acetate solution? (rather than of producing chloralhydrate and oxidising it or trichloroacetate) Important to me is that I really want the trichloroacetate, not mono- and dichloroacetate, because they have a different behaviour in complexation.

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