[beheada]

I read a workup for quinone from hydroquinone that used CrO₃. After reading that I stumbled upon this link about the oxidation using AgNO₃.

http://www.uni-regensburg.de/Fakultaeten/nat_Fak_IV/Organische_Chemie/Didaktik/Keusch/p14_hyd_ag-e.htm

If the silver precipitates is what's left in solution quinone (aq) and NO₃^-(aq)? And if that's the case, shouldn't there be a way to separate it from the nitrate without having to go through the trouble of the CrO₃ method of keeping the temperature controlled?

Just a ponderance...

[woelen]

Hydroquinone can also be oxidized with NaClO3/dilute H2SO4, with a small amount of V2O5 as a catalyst. This method works very nice and yellow crystals of quinone separate from the liquid.

[beheada]

Hydroquinone can also be oxidized with NaClO3/dilute H2SO4, with a small amount of V2O5 as a catalyst. This method works very nice and yellow crystals of quinone separate from the liquid.

I've got the vanadium pentoxide and the sulfuric acid, but I've been reading about sodium chlorate and I can't figure out a way to make any. According to wikipedia:

"It is synthesised from the electrolysis of hot sodium chloride solution in a mixed electrode tank. It can also be synthesised by passing chlorine gas to a hot sodium hydroxide solution. It is then purified by crystallization."

Now... I could do the chlorine method, but I don't really want to mess with chlorine gas because it's poisonous. I can't seem to find anything more specific about the synthesis of sodium chlorate, so I was wondering if anybody had any experience with making it? If I wanted to electrolyze the brine solution, would I just need to get a DC converter (like for a cell phone) and then stick both ends into the water (the way I oxidized an iron nail to make some rust?)

Hints, suggestions, links?

[beheada]

After further digging, I found this site as a link off woelen's site which explains in full detail the theory of producing chlorates. It's a really nice resource and very informative, so check it out.

http://www.wfvisser.dds.nl/EN/chlorate_EN.html

[pantone159]

Hydroquinone can also be oxidized with NaClO3/dilute H2SO4, with a small amount of V2O5 as a catalyst. This method works very nice and yellow crystals of quinone separate from the liquid.

Will this work just as well with potassium chlorate?

[woelen]

Not as good as with NaClO3. This is due to the limited solubility of KClO3 in water.

[pantone159]

Well, I might have to try it with the K chlorate, as I have it (but not the Na salt), and chlorates are getting troublesome to find now.  Hopefully it will still work, even if slower or a little less yield.

I plan on following the procedure from Organic Syntheses Coll. Vol 2, p 553, which I assume is the procedure that you (woelen) is referring to.