I have about a pound or two of cyanuric acid, and while looking at the structure I thought of deoxygenating the molecule to remove the hydroxyl or
carbonyl groups (depending on the tautomer) to form s-triazine which can be used as a solid replacement for hydrogen cyanide in a variety of
reactions. However, I am unsure what the best way to deoxygenate the molecule would be without damaging other parts.Praxichys - 9-9-2015 at 10:39
Why not use an acidified cyanide salt as a solid replacement for hydrogen cyanide?
I wonder what would happen if cyanuric chloride was reduced with sodium hydride? DFliyerz - 9-9-2015 at 11:02
Why not use an acidified cyanide salt as a solid replacement for hydrogen cyanide?
I wonder what would happen if cyanuric chloride was reduced with sodium hydride?
Well partially because you need hydrogen cyanide or a non-OTC ferricyanide salt to make cyanide salts, where as cyanuric acid is very OTC.Nicodem - 9-9-2015 at 11:19
To prepare s-triazine from cyanuric acid, you would first need to nucleophilically chlorinate it (oxalyl chloride?, or with
POCl3/PCl5 as in DOI: 10.1002/jlcr.3025), then hydrogenate the so formed cyanuric chloride. As far as I could find, there is no
such a reaction described in the literature, but there is an example of cyanuric chloride thiolation and desulfurisation with Raney Ni to give
s-triazine (DOI: 10.1021/jo01112a013). Direct hydrodechlorination might be unfeasible as triazines would be expected to poison Pd or Pt,
though it might work with Raney Ni.
I wonder what would happen if cyanuric chloride was reduced with sodium hydride?
Trisodium isocyanurate.
Sodium hydride is a lousy reducing reagent. It is excellent at reducing protons to hydrogen, but that is just about all it can do. There is almost no
example in the literature of sodium hydride reducing anything else as such, though it can be used in reactions with some Lewis acids to produce
soluble hydride reagents that are reducing reagents.Praxichys - 9-9-2015 at 11:43
IIRC +1 metal cyanurate salts (sodium, potassium) decompose to their corresponding cyanates and finally cyanides at about 800C. I have manufactured
calcium cyanamide using this route by making calcium cyanurate, then roasting to the cyanate, but ending on the cyanamide since Ca is a +2 metal. In
my research I read warnings about +1 metal contamination and the potential for cyanide formation. I cannot confirm if this is true, or the conversion
rate, but it might be a clue.
Even if the conversion is only something like 10%, further workup is certainly possible. Leaching of the residues with water will theoretically afford
a clear solution of the +1 metal carbonate, cyanate, and cyanide. Treatment of this filtrate with ferrous sulfate will afford the ferrocyanide salt,
which could be isolated. The ferrocyanide can be converted to ferricyanide or used as-is to distill HCN into alcoholic KOH, yielding dry, pure KCN for
storage.
This isolation method could be a potential workup for some of the other methods out there that involve charcoal, nitrites, carbonates, etc., at high
temperatures.
