I reciently found that NaBr(99%, 1% 'other') and Cyanuric Acid (100%, yea right) are available at my local pool supply shop. Given that Cyanuric Acid decomposes into Cyanic Acid above 300C (from memory) we now have two interesting reagents...
CNOH and NaBr
These strike me as interesting options to produce CNBr which I hear is wonderfull to poison your pool to keep the neighbor kids away.
Now I have not done near enough organic or any other kind of chemistry to plot a specific pathway, but I am fairly sure that if you mix these directly you will not be happy. Too many "things" could be produced for me to imagine a reasonable selectivity and/or safe outcome (if such is possible with CN gas invited to the party).
My thoughts have tended towards making Hbr from NaBr (I know I have seen this somewhere in my books, but I havn't found anything from a quick index search or on the public web indexes) I will start flipping through pages next if someone can't just flame me for my forgetfullness and save me getting callouses on my other thumb as well.
This was my hope, although my brief search has not produced any web references so far.
HBr + CNOH --> CNBr + H20
I can only wonder what catalysts, solvents, pressure, temp, radiation, sonic forplay, quartz\titanium isolation or last ditch antidotes might be necessary... Or maybe my insomnia repressed subconcious is just trying to kill me. Who can tell?
TrickE
And on the eight day, God created Meth...
... and hasn't done much of anything usefull since!