Organikum
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Sodium cyanate from cyanuric acid
Thats a question.
Anybody done this?
Cyanuric acid decomposes by heating to cyanic acid, venting this into a solution of NaOH or sodium carbonate will yield sodium cyanate.
Thats right?
Think so at least.
Any advise for purification and extraction?
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chloric1
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Cyanates and such
Well, I would recommend putting excess cyanuric acid into a ball mill with anhydrous soda ash and mix well. Then I would melt them together and you
should have your cyanate. The reason I suggest Excess Cyanuric acid is to allow for decomposition to carbon dioxide and ammonia. I got this idea
from some thread on cyanide synthesis. The cyanate should react with pure carbon above 1000 degrees C to make the cyanide which can be remelted and
poured through Insulation cloth or dissolved in water, passed through diatamasous earth and flash evaporated in a shallow pyrex dish. Let me know
where your experiments take you 
Fellow molecular manipulator
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Polverone
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| Quote: | First, I found a British patent, (710143), that relates a method of preparing cyanates from cyanuric acid. In the patent they are concerned about
avoiding cyanide, but I am obviously NOT.
Quick summary of the patent: powdered alkali carbonates are mixed with powdered cyanuric acid and heated to about 520 C. If this is done in a carbon
dioxide atmosphere, there is no detectable amount of cyanide formed. The reaction is carried out in a closed steel vessel at atmospheric pressure.
Only about 2/3 of the stoichiometric amount of alkali carbonate should be used. If more carbonate is used, some remains unconverted to cyanate. If
less is used, some ammonium carbonate and other products form. |
This is from the old "preparation of cyanides" thread. I know that I did obtain sodium cyanate at least as an intermediate, but of course I
was heating much more strongly, and longer, with charcoal, to convert as much as possible to sodium cyanide.
I don't think aqueous methods are best for cyanate production. Cyanate easily hydrolyzes in warm water near neutral or in acid conditions, though
I believe it is more stable under strongly alkaline conditions. The classic lab preparation is fusing powdered alkali carbonates or hydroxides with
powdered urea. The cyanuric acid seemed to work well also and was easier to powder.
PGP Key and corresponding e-mail address
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Organikum
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Made the cyanate from recrystallized urea and sodium carbonate, worked well.
Purification ideas?
I know this is already here and on the HIVE - I plain ask for some spoonfeeding here as I am pressed on time.
regards
ORG
[Edited on 3-11-2004 by Organikum]
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S.C. Wack
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Recrystallization from water is recommended both by Inorg Syn (available for months now) and the Perrins' and Armarego's Purification of
Laboratory Chemicals (coming soon). It seems that the K salt is a better choice to make if one wants a pure product, due to recrystallization losses
of the Na salt by their method.
Inorg Syn uses alcohol precipitation of the aq. sol'n after neutralization with acetic acid, with the K salt. They didn't want to use a
large amount of alcohol to precipitate the Na salt, but that's them.
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