thebean - 8-1-2014 at 19:28
While reading about hydroquinone on Wikipedia I noticed that there is a synthesis carried out industrially only in China (I'm guessing because the
procedure has some dangerous intermediates) but it seemed useful to the home chemist. First aniline is oxidized by manganese dioxide to produce 1,4
benzoquinone. The 1,4 benzoquinone is then reduced (Wikipedia didn't name a specific reducing agent) to hydroquinone. I'm going to give it a go
sometime soon for the purpose of producing both hydroquinone as well as 1,4 benzoquinone. I'll experiment with various reducing agents and report back
soon hopefully.
violet sin - 8-1-2014 at 19:39
not totally helpful, but I found a few 1lb jars of hydroquinone at a small town photography shop. been there so long they were offering them half
price. check in your area if you need some perhaps. I know that this won't help with production at all, but 7.50$/lb not too bad. kinda old so I'm
not sure it would be pure any more, but Kodak brand 
they only had two and I passed but meant to go back for them. only bought 1lb jar of potassium persulfate 7.50$. they also had jars of sodium
metabisulfite and a bunch of powder pouches and various tins or jars of useful stuff. but just the 3 types of pure chems. everything else would have
needed separation. I was looking for some thiosulfate but no.
gravityzero - 8-1-2014 at 20:32
Good luck with your research and post any results. It looks like your on the right path. I looked into this a few years ago and was going to go down
the same pathway from aniline to 1,4 p-benzoquinone.
I never went through the process, but the literature makes it appear to be relatively straightforward.
For what it is worth, I also recall the purification of benzoquinone as being from sublimation. I would like to get a sublimation apparatus one day,
but a makeshift setup is easy enough and effective.
Nickdul - 8-1-2014 at 23:42
Quinone is easily reduced to HQ via sodium bisulfite, IIRC. Yields are quantitative. I'm actually doing the opposite, oxidizing HQ to quinone and then
attempting a reductive sulphonation back to a dihydroxybenzene sulphonic acid salt.
This could be helpful:
the first 4-5 pages discuss production methods
Attachment: Pages from 78-155b.pdf (379kB)
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