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JJay
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Yeah....
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sulfuric acid is the king
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Quote: Originally posted by JJay  | | I'm not really sure... I haven't tried it in quite some time, but the yield was nowhere close to the quantitative yield claimed in the patent... maybe
20%? |
Hmm,so your picture of crude product is not by bisulfate route?
Very interesting,wich method do you use then?
About recrystalizing...If you just use vacuum to evaporate ethanol,how can it be recrystalization?Or?I am confused little bit,sorry about that 
Right now i have no time and equipment,i must plan and improvise,then i will share my results with you,no problem.
[Edited on 13-1-2017 by sulfuric acid is the king]
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alking
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If your ethanol is anhydrous then you can concentrate and freeze it to recrystallize. I don't remember what the bisulfate route is, but I think there
is both water in it (in the alcohol I mean) and that it generates water. If so you will have to dry it first. Assuming it works as advertised I would
use a drying agent to dry the alcohol, filter off any solids which should remove any sodium sulfates, concentrate until it starts to look cloudy, then
cool. That should give you fairly pure crystals.
[Edited on 13-1-2017 by alking]
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sulfuric acid is the king
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Bisulfate route is from the patent.
The legend says even hydrated bisulfate takes water from the alcohol,and makes sulfate decahydrate...
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JJay
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It didn't seem to work as well as reported for me, although it did produce some product. At least one person reported fantastic success with it
earlier in this thread. Maybe someone can get it to work?
[Edited on 14-1-2017 by JJay]
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sulfuric acid is the king
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But which method do you use then?
[Edited on 14-1-2017 by sulfuric acid is the king]
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alking
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Do you have sulfuric acid of bisulfate? They both seem to work well enough and the cost is about the same, just do w/e is easiest for you.
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sulfuric acid is the king
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I have both.
Btw i wonder which method JJay use,'couse of materials...
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JJay
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I've tried both. Obviously, sulfuric acid is the king 
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sulfuric acid is the king
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Aha,thanks.
But do i need oleum or just concetrated acid,what about ethanol,must be anhydrous or can i with just 95%?
And where can i find that procedure little bit detailed?
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JJay
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I've never tried it with oleum, but that's probably the best way if you can get it and have the means to handle it.
Antocho said he got a quantitative yield of ethylsulfuric acid using this method: http://www.sciencemadness.org/talk/viewthread.php?tid=1113&a...
It's been suggested that sodium ethyl sulfate doesn't hydrolyze under heat in neutral conditions. That doesn't seem to be the case....
The method I've had most luck with is an adaptation of Cohen's synthesis of potassium ethyl sulfate using sodium carbonate instead of potassium
carbonate: http://www.prepchem.com/synthesis-of-potassium-ethyl-sulfate...
Use a drying tube and add the sulfuric acid very slowly with a dropping funnel and stirring in a ventilated area. Side products of making
ethylsulfuric acid can include diethyl ether and diethyl sulfate if you add the sulfuric acid too fast, so using a fume hood is not a bad idea. Should
you mess up, don't spend too much time enjoying the pleasant peppermint smell; that's a potent carcinogen.
I used anhydrous ethanol (it makes a huge difference) at 75% of the volume suggested by Cohen. Also, I heated the flask in a boiling water bath for
five hours and evaporated off excess water on a boiling water bath, decanting from the precipitated salts as the water is removed. The solution *must*
be alkaline, at least pH 9, when heating is started, or the entire product will be destroyed. I suspect that heating causes some decomposition even
under alkaline conditions but not everyone thinks so, and I have not rigorously verified this. You can get a reasonably pure product if you filter all
of the salts from a saturated solution of the sodium ethyl sulfate before removing the rest of the water. Crystals taken early on in evaporating the
saturated solution will be translucent or perhaps even clear when wet if you use extremely pure reagents.
Oh and sodium ethyl sulfate smells like laundry detergent.
[Edited on 15-1-2017 by JJay]
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| Quote: Originally posted by JJay |
It's been suggested that sodium ethyl sulfate doesn't hydrolyze under heat in neutral conditions. That doesn't seem to be the case....
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What makes you say this?
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JJay
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Read the thread. I've ended up with acidic product after starting with slightly neutral solution and heating.
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sulfuric acid is the king
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@JJay
Thanks so much.
Is there any method to know when is sulfuric acid totally used?
And what about some analytical method to confirm that i actually obtained right stuff (NaEtSO4)?
[Edited on 15-1-2017 by sulfuric acid is the king]
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alking
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| Quote: Originally posted by JJay | | Read the thread. I've ended up with acidic product after starting with slightly neutral solution and heating. |
Yeah, but you said there was H2O left after you evaporated off your ethanol so that was probably some sodium bisulfate wouldn't you think? I wouldn't
conclude that it necessarily hydrolyzed from that alone.
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JJay
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I don't think the sulfuric acid is ever totally used unless the water is removed somehow. I saw a paper on the reaction kinetics a while back which
suggested that it's hard to get much above 40% in equillibrium with ethanol and sulfuric acid, although someone did reportedly manage to get 70%
starting with completely anhydrous reagents. I don't remember the name of the paper offhand.... Water is a major yield killer as it slows the reaction
considerably and pushes the equillibrium in the wrong direction.
You can use the melting point and check other properties like its solubilities. I think you can also check its purity with a GCMS, and it will give
off ether if refluxed in sulfuric acid.
[Edited on 15-1-2017 by JJay]
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| Quote: Originally posted by sulfuric acid is the king | @JJay
Thanks so much.
Is there any method to know when is sulfuric acid totally used?
And what about some analytical method to confirm that i actually obtained right stuff (NaEtSO4)?
[Edited on 15-1-2017 by sulfuric acid is the king] |
What do you mean, totally used as in you get a quantitative yield on the H2SO4? The oleum route should do it. Supposedly wet EtOH and H2SO4 can be
used if you dry the solution with enough Na2SO4 to hold all of the water. For that matter the bisulfate route is supposed to do the same if you use an
excess of bisulfate, but JJay reports mixed results on that, I'm not sure the reason.
Analytical wise you could test the melting point (86C according to JJay), the PH (again, slightly alkaline according to JJay), it smells like laundry
detergent as he said, and visually if you were to recrystalize it you should see that the crystals are uniform. Likewise if your product fully
dissolves in anhydrous alcohol, and does not leave a cloudy suspension, then you can assume that it is the correct product as no other products in
either of these reactions has appreciable solubility in alcohols. This should be a straightforward synthesis, just give it a shot.
[Edited on 15-1-2017 by alking]
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alking
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| Quote: Originally posted by JJay | I don't think the sulfuric acid is ever totally used unless the water is removed somehow. I saw a paper on the reaction kinetics a while back which
suggested that it's hard to get much above 40% in equillibrium with ethanol and sulfuric acid, although someone did reportedly manage to get 70%
starting with completely anhydrous reagents. I don't remember the name of the paper offhand.... Water is a major yield killer as it slows the reaction
considerably and pushes the equillibrium in the wrong direction.
You can use the melting point and check other properties like its solubilities. I think you can also check its purity with a GCMS, and it will give
off ether if refluxed in sulfuric acid.
[Edited on 15-1-2017 by JJay] |
I read a paper on the H2SO4, EtOH, and Na2SO4 route that claimed 'quantitative yields.' The oleum paper claimed 86% yields. Antiocio(sp?) also claimed
'near quantitative' yields with the Na2SO4 route. I would go with that. The way you do it according to the paper is to drip in the H2SO4 slowly so
that it doesn't get too hot to minimize side products. After it's returned to room temperature you grind your Na2SO4 into a fine a powder as possible
to maximize surface area and add it slowly into the solution while it is stirring to evenly disperse the salts. Then you leave it overnight, ~12
hours, or w/e. The Na2SO4 should grab onto all of the water during that time and as it does the reaction will go to completion.
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JJay
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| Quote: Originally posted by alking | | Quote: Originally posted by JJay | I don't think the sulfuric acid is ever totally used unless the water is removed somehow. I saw a paper on the reaction kinetics a while back which
suggested that it's hard to get much above 40% in equillibrium with ethanol and sulfuric acid, although someone did reportedly manage to get 70%
starting with completely anhydrous reagents. I don't remember the name of the paper offhand.... Water is a major yield killer as it slows the reaction
considerably and pushes the equillibrium in the wrong direction.
You can use the melting point and check other properties like its solubilities. I think you can also check its purity with a GCMS, and it will give
off ether if refluxed in sulfuric acid.
[Edited on 15-1-2017 by JJay] |
I read a paper on the H2SO4, EtOH, and Na2SO4 route that claimed 'quantitative yields.' The oleum paper claimed 86% yields. Antiocio(sp?) also claimed
'near quantitative' yields with the Na2SO4 route. I would go with that. The way you do it according to the paper is to drip in the H2SO4 slowly so
that it doesn't get too hot to minimize side products. After it's returned to room temperature you grind your Na2SO4 into a fine a powder as possible
to maximize surface area and add it slowly into the solution while it is stirring to evenly disperse the salts. Then you leave it overnight, ~12
hours, or w/e. The Na2SO4 should grab onto all of the water during that time and as it does the reaction will go to completion.
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You can get quantitative yields with oleum. The route with Na2SO4 looks nice in theory, and I certainly intend no disrespect towards Antoncho, but
call me skeptical. If you'd like to try it and report back, by all means do so.
Also, I have no idea what paper you're talking about.
[Edited on 15-1-2017 by JJay]
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Here you go. https://www.google.com/patents/US3047604
I might give it a shot if I can find some free time just for curiosities sake, it looks easy enough.
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JJay
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Why would sodium sulfate be more hydrophilic than ethanol, sulfuric acid or even ethyl sulfate? Also, there's the problem of surface area; the water
molecules can really only attach to the sodium sulfate on the outside of the sodium sulfate particles, requiring a large excess of desiccant, right?
I'm not saying that I'm 100% sure it can't work, but I was disappointed by the results of testing another of Mr. Leatherman's patents that made
similar claims, so I'm not convinced that it actually does work.
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| Quote: | | [quote=472024&tid=1113&author=JJay]Why would sodium sulfate be more hydrophilic than ethanol, sulfuric acid or even ethyl sulfate? Also,
there's the problem of surface area; the water molecules can really only attach to the sodium sulfate on the outside of the sodium sulfate particles,
requiring a large excess of desiccant, right? |
I don't know, that's just what the patent claims. Even if EtOH or H2SO4 were more hydrophobic if Na2SO4 is more hydrophobic than HEtSO4 as Na2SO4
grabs some of the water the equilibrium would constantly shift and any free EtOH and H2SO4 would form, further shifting that equilibrium so that
Na2SO4 could grab more water and so on until it's shifted all the way to the right. There's likely traces of EtOH and H2SO4 remaining at least, but
theoretically it makes sense.
[Edited on 15-1-2017 by alking]
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sulfuric acid is the king
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Simply.When i said totally used i thought reacted to form ethylsulfuric acid,diethyl sulfate,diethyl ether...
Why i ask that?To know what to expect,if i neutralize mix i will get more NaHSO4 contamination etc...
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Oh, and I forgot to address the later question. That's why you grind it into a powder and add it as a fine stream, because of the surface area issue.
They address that in the paper.
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| Quote: Originally posted by sulfuric acid is the king | Simply.When i said totally used i thought reacted to form ethylsulfuric acid,diethyl sulfate,diethyl ether...
Why i ask that?To know what to expect,if i neutralize mix i will get more NaHSO4 contamination etc... |
You'll have bisulfate contaminant regardless, but as I said earlier it's easy to filter off. Someone mentioned as well that once your H2O/EtOH is
saturated with NaHEtSO4 that all the sulfates crash out (besides the product of course). Filter at that point and you're good. From there dry it and
optionally recrystallize it.
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