LD5050
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Recrystalizing ammonium methyl sulfate?
I made some ammonium methylsulfate by refluxing MeOH and sulfamic acid. I now have a really crude dirty product as some of the sulfamic acid charred
in the process. I now am looking to find a way to purify it by recrystalization but I can't find any info on this Chem. Does anyone know what I could
use for solvent?
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JJay
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That's going to be tricky even without any charring... if it's charred, I'd suggest just scrapping it and starting over... you're probably looking at
ammonium sulfamate, sulfamic acid, ammonium methyl sulfate, and possibly even methylamine and bisulfate and/or sulfate salts at this point... who
knows, maybe even [bi]sulfites and/or dimethyl sulfate... you can heat the reaction with a boiling water bath, so there is absolutely no reason to
tolerate any charring.
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LD5050
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The problem was the sulfamic acid wouldn't dissolve it ended up taking around 4 hours to completely dissolve at a strong reflux and initially the stir
bar wouldn't spin and in that time some of the sulfamic acid charred i should have kept a closer eye but I didn't, I decided to still go on with
synthesis hoping I would still get desired product...
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JJay
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I haven't tried this, but I think you can remove sulfamate from the reaction product between sulfamic acid and methanol by dissolving in water,
stirring with an excess of finely powdered barium carbonate, and filtering. After that, I am pretty sure you can evaporate off the water and
recrystallize from methanol, but the product might contain some barium... you could probably remove that by recrystallizing from dilute ammonium
hydroxide.
If it's charred, though, all bets are off because it will be very difficult to separate the ammonium methyl sulfate without destroying the methyl
sulfate ions.
[Edited on 12-6-2017 by JJay]
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JJay
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Quote: Originally posted by JJay  | I haven't tried this, but I think you can remove sulfamate from the reaction product between sulfamic acid and methanol by dissolving in water,
stirring with an excess of finely powdered barium carbonate, and filtering. After that, I am pretty sure you can evaporate off the water and
recrystallize from methanol, but the product might contain some barium... you could probably remove that by recrystallizing from dilute ammonium
hydroxide.
If it's charred, though, all bets are off because it will be very difficult to separate the ammonium methyl sulfate without destroying the methyl
sulfate ions.
[Edited on 12-6-2017 by JJay] |
I was just researching the best way to make potassium methyl sulfate, and I ran across this old post. This doesn't work; barium sulfamate is too
soluble.
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