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tom haggen
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Ethyl Iodide
I've been trying to find a synthesis for ethyl iodide today on google, and so far I haven't come up with much. So maybe I can just take a
shot in the dark. I'm thinking that you could react NaI with CH3CH2OH and get ICH3CH2 maybe using vacuum distillation? So would the reaction go
like this?
CH3CH2OH + NaI --> ICH3CH2 + NaOH
This seems convenient because both precursors are available over the counter.
[Edited on 25-10-2004 by tom haggen]
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S.C. Wack
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No, you will get NaI dissolved in EtOH.
Google is not what you should be reading, a number of texts have the synthesis of ethyl iodide in them. You will help yourself and everyone else by
reading them, then making some and reporting back.
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kyanite
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Heads up that theres always the highly illegal route including HI acid...
HI + EtOH => EtI + H2O
Bromine will do the same, just search it up.
Like S.C. said, alot of chem textbooks have information like this. Thats where I looked...
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BromicAcid
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HI is also a powerful enough acid to reliably cleave ethers therefore, reaction of HI with Et2O will yield EtOH and EtI respectively. A mixture of
phosphorus or possibly sulfur with nearly anhydrous EtOH and I2 with distillation would yield the desired product. (I've seen sulfur substituted
for phosphorus in a number of reactions similar to this, but only with chlorine and occasionally bromine, iodine does not even have the power to make
any compound with sulfur and therefore it may not have any effect at all.)
Maybe something involving insitu use of carbonyl iodide?
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tom haggen
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Hydriodic acid sounds way to dangerous for my liking. Also I was kind of looking for something along the lines of easily obtainable chemicals. By the
way what the hell is so illegal about the HI + EtOH route? I haven't seen ICH3CH2 listed as a watched chemical?
[Edited on 25-10-2004 by tom haggen]
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neutrino
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HI is a list I meth precursor, i believe.
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BromicAcid
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Somewhat concentrated (60%) H2SO4 w/ NaI and EtOH might feasibly be heated and the EtI obtained by distillation (in the dark of course). However the
catch of the matter is if your H2SO4 is too concentrated or if your temp goes too high or any of a number of other things happen, actually it probably
happens all the time, it's just the rate. The I- will be oxidized by your H2SO4 and give you sulfur dioxide, water, elemental iodine and other
undesirables.
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kyanite
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It's not the route thats illegal, but the hydriodic acid. It is a controlled precursor here in North America with heavy penalties. In the US,
it's schedule I and thus a watched chemical by the DEA.
Looking over the Canadian Schedules, it looks like hydriodic acid isn't on any of the lists! Can someone verify this?...
Edit: Bromic Acid, in the method you're describing, the HI is made kind of like in situ right? Question: Why do you think light will effect the
reaction?
[Edited on 25-10-2004 by kyanite]
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tom haggen
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Well that cancels out the HI method. Unless I synthesize my own from H2S and Iodine which isn't going to happen cause H2S is not my buddy. So....
I could try using H2SO4 with NaI, and EtOH, and maybe distill with a vacuum. But why do I need to do this in the dark? Oh ya and hopefully that
reaction would let off any H2S thats what would scare me.
[Edited on 25-10-2004 by tom haggen]
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Marvin
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One of the more recommended methods is phosphoric acid + sodium iodide to form the HI distilling over the ethyl iodide.
Another possibility is to make ethyl bromide and react with NaI to end up with ethyl iodide and sodium bromide. The problem here is that if you jump
to chloride instead you end up making gasses which are harder to handle.
Alkyl iodides tend to decompose somewhat in light turning brown from free iodine.
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tom haggen
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So, inconclusion.
H3PO4 + NaI --> HI + H2 + NaPO4
HI + EtOH --> ICH3CH2 + H20
Whats a good way to remove the sodium phosphate? Distilling the HI I assume would do the trick. that seems like a pain in the ass...
[Edited on 26-10-2004 by tom haggen]
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kyanite
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Whaaaaa.....
Sorry for being hypocritical, but the first reaction maybe should be
H3PO4 + NaI -> HI + NaH2PO4 because the acid ionizes 3 times.
You might also be able to get more HI for your phosphoric by reacting 2 more moles of NaI like you can with carbonic acid. You'll probably need
to heat it though.
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tom haggen
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Ok well theres already tones of information all over the place on this subject so I guess I wasn't looking hard enough. Sorry if I took up some
unecessary space.
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acx01b
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H2SO4 75%-80% (drain cleaner, toilets cleaner in all drugstores all other the world just ask for the drain cleaners you will find it) and Toluene
(same place) are refluxed for 30min
organic phase is separated while still hot (>60°C) to get toluenesulfonicacid monohydrate
with 99% H2So4 the yield is 99%....
with 80% i dont know
then this is mixed with any alcohol except phenol and phenol like alcohols...
to get toluenesulfonic ester
then this is reacted with NaX...
to get sodium toluenesulfonate and R-X
last step is separation and i really dont know: i remember that toluenesulfonate are used as detergents (solubility in organics and water)
by the way toluenesulphonic acid monohydrate can be purchased
[Edited on 28-10-2004 by acx01b]
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tom haggen
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What the hell are you going on about acx? What does toluene sulfonic acid monohydrate have to do with this subject? BTW, bromic acid, how possible do
you think your method might be to actually working? The only thing that I see that would actually contaminate the ethyl iodide would be SO2 and H2O
which seem like they could be removed from further distillation. I just realized something, the NaI that they sell at the grocery store is
NaI(aqueous) and its already a very brown color. So it probably wouldn't work for this application.
[Edited on 28-10-2004 by tom haggen]
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unionised
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I presume he is going on about making the sulphonic acid to prodce a ethyl sulphonate to react with NaI to give ethyl iodide which seems to have quite
a lot to do with the topic.
The brown colour of the NaI soln is probably due to free iodine and is easy enough to remove. titration with bisulphite seems like a good start.
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Tacho
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I have produced METHYL iodide a few times. The yield varies wildly with small changes in the reactant ratios and reaction conditions. The best yield I
ever got was mixing 25gKI (0,15mol), 25ml 85% Phosphoric acid (0,37 mol), 25ml of methanol (0,62mol) and 0,1g of iodine crystals. This was brought to
gentle reflux for 1 hour using ice-cold water in the condenser and magnetic stirring, then the reaction was left for 24 hours in a closed flask.
Finally it was fractionally distilled (with magnetic stirring!) to give 6ml of MeI (13,7g, 0,096mol) a 64% yield.
You add some water to the distilate to obtain two phases, the lower is the very volatile iodide.
Would the yield be lower without the iodine crystals? I don’t know.
Does it have to be refluxed a bit and left for 24 hours? In my experience, yes. Be my guest to try something different.
For fractional distillation I used two condensers in series, one going “up” with water at 22°C (ambient), and the other going down, with ice-cold
water. The receiving flask was kept in a ice-water mix.
I believe this would work for ethyl iodide using ethanol instead of methanol.
I was always VERY CAREFUL doing this reaction. Some sources say that methyl iodide is very nasty stuff (methylate your DNA) and the leftovers of the
reaction are organophosphoric poisons. Ethyl iodide is probably no better…
This reaction is one of my sentimental favorites though. I figured it out by myself before I found it in the internet. Not being a chemist, I felt
quite proud of it. My ignorant-but-sucessful reasoning was: If the acid(H2SO4)-alcohol(ethanol)-salt(NaBr) mix works for making ethyl bromide, some
combination of them should work for methyl iodide. After many microscale experiments, there was the little brown drop in the bottom of the testube.
If you don’t like it brown, some dilute NaOH brings it to it’s natural lack of color.
Wish you luck. Be careful though…
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kyanite
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Apparently hydriodic acid is an amazing reducer, and becasue of that it can't be made from reducable acids like sulfuric and maybe even phosporic
acid without the yeilds suffering from the HI oxidizing. Thats why a lot preparations use H2S.
Good ol' Rhodium:
http://www.rhodium.ws/chemistry/hydriodic.html
http://www.rhodium.ws/chemistry/hydriodic.argox.html
Maybe isolation, then use of the HI can give more accurate information on yeild.
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alchemie
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Here´s another route, using I2, Al foil, EtOH and H2SO4, also from Rhodium´s page:
http://www.rhodium.ws/chemistry/nitroalkane.html
I suppose the HI is produced in situ from hydrolysis of AlI3 formed from I2 and Al foil.
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thunderfvck
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I remember being interested in doing this. It's outlined in Vogel and he uses red phosphorous and iodine. Both can be obtained OTC, may arrouse
some suspiscious but if you're only going to be using it for ethyl iodide there should be no problem.
I can write out the procedure for it later on tonight when I'm not so late for work.
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trilobite
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Maybe the latter of these two methods could be adapted for ethyl iodide as well. Why waste phosphorus for this?
https://www.the-hive.ws/forum/showflat.pl?Cat=&Number=30...
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Darkfire
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Anyone thought of h2so4 and NaI in DMSO then the ethanol or ether?
\"I love being alive and will be the best man I possibly can. I will take love wherever I find it and offer it to everyone who will take it. I
will seek knowledge from those wiser and teach those who wish to learn from me.\" Duane Allman
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Eclectic
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There are some preparations of alkyl bromides in a book I have, "Bromine", that use bromine dripped into a stirred mixture of the alcohol
and sulfur. Maybe a similar route would work with I2?
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garage chemist
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The method from Tacho seems to be the best.
Phosphoric acid is non- oxidizing and therefore very useful for this reaction.
The standard method for ethyl iodide production is ethanol + red P + iodine, but only useful if you have enough red P.
Tom, why does it have to be ethyl iodide? Ethyl bromide works just as well for many reactions and is easily prepared from NaBr, H2SO4 and ethanol.
What are you going to use the ethyl iodide for?
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tom haggen
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I want to use it for a diethylamine synthesis. I'm haven't taken o-chem yet so I'm kind of getting ahead of myself. I'm pretty
sure you can synthesize diethylamine from Ethyl Bromide but I don't know how easily NaBr is obtained. Anyway this question was more out of
curiosity than anything.
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