I'm sitting here looking at the COPAE article on Trinitrotriazidobenzene, which starts out with trichlorobenzene... And I realize I've got some Hexachlorobenzene in my stores (used by us as a Chlorine donor in certain pyrotechnic formulations, primarily colored AP/Magnesium strobe stars). Any possible routes to this product from the Hexachlorobenzene come to mind?

None that I can think of. Big Cl's and the ring itself cause lots of hinderance, making any attack less likely, and those Cl's won't leave because there's nothing electron-withdrawing on the ring - in the synth. of TATNB, the nitro's have to be put on before the Cl's can be replaced. And you can't put on any nitro's without replacing a Cl...

Best to use it for pyrotechnics :).

None that I can think of.
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Best to use it for pyrotechnics :).

I kind of figured-

Oh well, it's going to go for the original use. BTW, it's HARD to find in the US market anymore, carcinogenic & such. Used to be the most popular chlorine donor for a while after WWII.

patent search pulled up plenty of hits on degrading it as a remediation technique.

Partial degradation might be possible, to strip off just a few of the chlorines.

Come to think of it, how'd you go about preparing hexachlorobenzene anyway? My guess would be to reduce the nitro groups of 1,3,5-trinitrobenzene to amine groups using Sn/HCl, chlorinate the product with excess Cl2 in the presence of FeCl3 , followed by replacement of the amine groups by Cl via the diazonium route. Will this method work, or is there some better method?

I would be worried the chlorination reaction would damage the amine groups.

You will be dissapointed at the industrial methods. To deliberatly make it you can simply react benzene with excess chlorine using ferric chloride catalyst at 200C or so. Large amounts turn up industrially as byproducts when making other chlorinated chemicals like perchloroethylene and its retained very well by fractionating columns. They have to either dispose of it or sell it.

Well, I'd expect just that from industrial methods. It's strange how the worst laboratory methods make great industrial methods, though! What a waste, just disposing of it, especially since it's so hard to find nowadays.

In COPAE it gives a violent preparation of HCB. You react Chloroform with Sodium metal. Looks like a fun demo, but It would be difficult to collect the HCB.