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Author: Subject: What exactl is ortho-chloranil?
MNK
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[*] posted on 3-9-2008 at 06:10
What exactl is ortho-chloranil?


I can already see the posts instructing me to google it so dont bother, I already have, and I've found nothing but complex articles discussing very specific applications of the product/substance. What I'm hoping for here is a general discription of ortho-chloranil, and if possible, any information relating to its purchase.

Thanks
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[*] posted on 3-9-2008 at 06:16


It is 3,4,5,6-tetrachloro-orthobenzoquinone

A quick look at this article should make it clear

http://en.wikipedia.org/wiki/Quinone

Buying it?

Tricky unless you have access to Sigma Aldrich and their ilk.

Apart from that you may get lucky and be able to order some from a photographic supplier that deals in raw chemicals if you can convince them that you are into heavy DIY developing.

Oh and it is not cheap!

http://www.sigmaaldrich.com/catalog/search/ProductDetail/ALD...

[Edited on 3-9-2008 by ScienceSquirrel]
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Nick F
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[*] posted on 3-9-2008 at 08:29


Catechol + XNO3 + HCl, if you can't buy it?
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[*] posted on 3-9-2008 at 09:48


Quote:
Originally posted by Nick F
Catechol + XNO3 + HCl, if you can't buy it?


He really needs a recipe for that.

The problem with organic reactions is getting a decent yield and isolating the product.
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[*] posted on 3-9-2008 at 09:52


To give you possibly an idea of what's involved, here is an outline of the synthesis of the para-isomer starting from hydroquinone:

Quote:
. A process for the preparation of tetrachloro-1,4-benzoquinone from hydroquinone in the presence of an aqueous medium containing chlorine and hydrochloric acid, which comprises the steps of:


providing an aqueous medium containing iron (III) ions as a catalyst, an anionic dispersant, and hydrochloric acid in a concentration of 20 to 37%, said hydrochloric acid being provided in a 4 to 6 times molar amount based on the total amount of hydroquinone to be added in said process;
dividing said total amount of hydroquinone into space-time yield-improving portions and introducing a first portion of the hydroquinone into said aqueous medium; introducing 1.5 to 2.0 times the molar amount, based on said total amount hydroquinone, of chlorine as a gas into the aqueous medium at a temperature of from 20.degree. to 90.degree. C. in a first chlorine addition; adding the remaining portion of hydroquinone; introducing 1.5 to 2.0 times the molar amount, based on said total amount of hydroquinone, of chlorine as a gas in a second chlorine addition; holding the concentration of the hydrochloric acid in the aqueous medium at 23-25% by addition of water; raising the temperature to 100.degree. to 107.degree. C. while introducing additional chlorine gas at 1.7 to 2.5 times the total molar amount of hydroquinone in a third chlorine addition; and diluting the aqueous medium with water to a hydrochloric acid concentration of from 20 to 22%.




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[*] posted on 3-9-2008 at 11:52


There was quite a bit of discussion on the para isomer in energetics IIRC, since it was being looked into as a precursor for a tetraazide primary explosive. I don't often read that forum so I do not remember how the synthesis went. I imagine the ortho isomer is nearly identical in preparation but using ortho-benzquinone (oxidation of pyrocatechol perhaps) instead of the para isomer.



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[*] posted on 3-9-2008 at 12:55


An older reference (Organic Reactions vol. 4, p. 316) gives the prep method as the oxidation of tetrachlorocatechol with nitric acid to give an 81% yield. Ref: Am. Chem. J. 1907, 37, 11. Reference is made to running the reaction in either acetic acid or ethanol. The halogenated o-quinones are described as being 'sufficiently stable.'

This patent gives a continuous lab-scale process for making o-chloranil from tetrachlorocatechol via chlorination of catechol & nitric acid oxidation: http://www.pat2pdf.org/patents/pat4196132.pdf





[Edited on 3-9-2008 by Ritter]




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[*] posted on 3-9-2008 at 23:03


Thanks guys, much appreciated
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[*] posted on 7-9-2008 at 08:09
Chloranil


Don't know what are you goung to use it for, but DDQ is a substitute in many processes.
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