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Siddy
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What are the thoughts on thiourea dioxide working on aliphatic nitro's to amines?
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Barium
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I doubt it will reduce a aliphatic nitro group all the way to the amine. But hey, try it! Add a couple of equivilents to a milliliter of nitromethane
and see if there is a reaction. Let us know the results.
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Siddy
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Yeah, its a shame thioure dioxide has no common sources.
Another idea,
What about coupling thiourea dioxide with ammonium chloride/zinc?
Zinc/Ammonium chloride gets it half way (to hydroxylamine) and then thiourea as hydride source to finish it off? It might be more effective than
zinc/ammonium foramte.
eg, R.T. stirring of nitromethane with fresh zinc power, ammonium chloride and thiourea dioxide.
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Paddywhacker
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Thiourea dioxide should be available from the same type of shops that sell raw indigo for dyeing.
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Nicodem
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...as well as specialized shops that sell chemicals for photography developing (for example, one of the most known companies, Silve***int, sells it
for £15.00 per 100g). It would be good to actually first check the catalogues of the "common sources" before claiming they do not sell it,
particularly since it was already mentioned in this thread earlier that one needs not to acquire it trough chemical sellers.
Ammonium chloride is an acid, therefore you can not use thiourea dioxide for reductions in its presence. Besides, I fail to see the point. Zinc in the
presence of HCl reduces nitroaromatics and nitroaliphatics all the way to amines.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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Magpie
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In searching for an OTC source of sodium dithionite (SD) I found that the hobbyist dye suppliers have replaced it with thiourea dioxide (TUD). This
seems due to the fact that SD cannot be shipped by air, as it is hazard class 4.2 (spontaneously combustible). TUD is also classed 4.2 but still
seems to be readily available. Go figure. The dye people say TUD is 5 times as potent as sodium dithionite. This may be another reason it is
replacing SD. I couldn't find an OTC source of pure SD.
I'm having a difficult time learning just how TUD works. It has the formula (NH2)(NH)C(S)O(OH), and is aka aminoiminomethanesulfinic acid. In
alkaline aqueous conditions with some heating it breaks down to urea and sulfoxylic acid (H2SO2) by adding one molecule of water, I guess. It seems
that this non-isolable sulfoxylic acid, or the sulfoxylic anion, SO2(2-) is the specie that actually does the reducing, ie:
SO2(2-) ----> SO2 + 2e- .........(I theorize)
If anyone can verify or correct my assumptions about TUD please do so.
Edit: Looking further it seems that the actual reductant and products of the reduction are dependant on the nature of the oxidant and the reaction
conditions. This I think is true of all reaction scenarios, redox or otherwise.
[Edited on 12-5-2010 by Magpie]
[Edited on 12-5-2010 by Magpie]
The single most important condition for a successful synthesis is good mixing - Nicodem
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Magpie
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In searching the OTC market for sodium dithionite I found RIT Dye's "White-Wash." The package lable says it contains sodium hydrosulfite and
anhydrous sodium carbonate.
A Dutch paper, kindly posted by ayush, provided an assay method using redox titrimetry. 0.1N potassium ferricyanide is used as the oxidant; methylene
blue is used as indicator. The titration flask must be kept flushed with an inert gas to prevent the air oxidation of dithionite which oxidizes with
extreme ease. I used argon, which being heavier than air, worked well.
It still is a tricky assay, and I ran it several times before I was satisfied. For paper I used a 3" square of one ply of toilet paper. The result
was 86% sodium dithonite dihydrate.
[Edited on 20-5-2010 by Magpie]
The single most important condition for a successful synthesis is good mixing - Nicodem
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mnick12
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Thiourea dioxide synth
I found this thread interesting, and thought that I would have a go at thiourea dioxide they way the did in the article posted. Everything was the
same except I did it at 1/10th the scale. The reaction was easy to do but I ended up with 1.81gr of dry product from the 3.8g of thiourea. So my
question is do I have to dilute the H2O2 so much, or can I leave it at 30% and save my product from being carried away in the finished solution?
Also has anyone here conducted any experiments reducing compounds with thiourea dioxide? If not I am open for any ideas.
Oh and I may post a few pics on thiourea dioxide synth sometime soon if anyone is interested.
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Formula409
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Quote: Originally posted by mnick12  | I found this thread interesting, and thought that I would have a go at thiourea dioxide they way the did in the article posted. Everything was the
same except I did it at 1/10th the scale. The reaction was easy to do but I ended up with 1.81gr of dry product from the 3.8g of thiourea. So my
question is do I have to dilute the H2O2 so much, or can I leave it at 30% and save my product from being carried away in the finished solution?
Also has anyone here conducted any experiments reducing compounds with thiourea dioxide? If not I am open for any ideas.
Oh and I may post a few pics on thiourea dioxide synth sometime soon if anyone is interested. |
Thanks for giving it a go! I used approx 50% H2O2 in the synth with the amounts changed to give the same stoichiometry and I got pretty low yields too
(30-40%). Maybe the patent is just trying to sound better than it actually is? I also tried with the H2O2 diluted to 30% but got identical yields.
For trying reductions, camphor seems to be a great choice as the reactions are already documented and it is available OTC pure and reasonably priced!
Formula409
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Nicodem
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| Quote: Originally posted by mnick12 | | Also has anyone here conducted any experiments reducing compounds with thiourea dioxide? If not I am open for any ideas. |
I would suggest an attempt at reducing vanillin. I suspect that under properly basic conditions it would get reduced all the way to
4-hydroxy-3-methoxytoluene (trough the quionone methide intermediate). Even though I have some strong suspicions about the paper linked bellow of
being just one of those numerous typical fictional stories,* I would nevertheless try using their experimental in such an attempt (obviously with a
double amount of thiourea dioxide for vanillin), it's a typical procedure anyway:
ARKIVOC, 2009, 141-145.
* There are plenty of papers claiming this reagents reduces nitroaromatics to anilines under similar conditions. Besides, my BS detector goes wild in
such cases due to the unfortunate frequency of fictional papers coming from India&Iran&Co. combined with certain weird things of which maybe
the weirdest one is the oxygen content measured with an elemental analysis! Besides, the products are known compounds and they don't even give melting
points and back them up with references. Another improper thing is in that they did not include any references for the nitroaromatics being reduced
with thiourea dioxide. I'm sorry to say this, but whoever was the peer reviewer for this paper truly did a very lousy job.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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mnick12
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I like both of your ideas,but I have a few comments.
Formula you said that camphor is OTC, I know it is used in some soaps and things like that, but is it available as a pure material?
So camphor would be reduced to Borneol?
Nicodem,
I like the idea of reducing vanillin, but I do not have access to it in a pure form. Though I may be able to get some ethylvanillin, but it will be
few weeks before I can get it shipped. Oh one more thing the paper you kindly shared mentioned the reduction of nitroketones and nitroaldehydes, but
do you know if TUD is capable of reducing carboxylic acids?
Thanks.
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Nicodem
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| Quote: Originally posted by mnick12 | | Oh one more thing the paper you kindly shared mentioned the reduction of nitroketones and nitroaldehydes, but do you know if TUD is capable of
reducing carboxylic acids? |
No, it can not reduce carboxylic acids.
Another paper from the same authors as above is in the attachment (DOI: 10.1080/00397910802026220). This time I leave it to the reader to judge
whether it is science or science fiction. Note they claim p-hydroxybenzaldehyde reduces to p-hydroxybenzyl alcohol using 1 equivalent of thiourea
dioxide. It would be interesting to test this on vanillin (or "ethyl vanillin"). If would also be interesting to test the reduction of vanillin using
double amounts of thiourea dioxide and NaOH, without EtOH cosolvent (a cosolvent is not needed as vanillin dissolves well in aqueous NaOH) and longer
reflux.
Attachment: Novel Chemoselective Reduction of Aldehydes in the Presence of Other Carbonyl Moieties with Thiourea Dioxide.pdf (151kB)
This file has been downloaded 3420 times
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Formula409
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| Quote: Originally posted by mnick12 | I like both of your ideas,but I have a few comments.
Formula you said that camphor is OTC, I know it is used in some soaps and things like that, but is it available as a pure material?
So camphor would be reduced to Borneol?
|
Have a look at mothballs - depending where you are from they should contain fairly pure camphor. There are also p-dichlorobenzene ones, but in
Australia they don't sell them at all.
Hope this helps!
Formula409.
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DJF90
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Some mothballs are Naphthalene...
[Edited on 8-6-2010 by DJF90]
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Paddywhacker
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| Quote: Originally posted by mnick12 | I like both of your ideas,but I have a few comments.
Formula you said that camphor is OTC, I know it is used in some soaps and things like that, but is it available as a pure material?
So camphor would be reduced to Borneol?
... |
See this photo, but don't let the manji freak you out.
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Magpie
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Yes, I have some Enoz "old fashioned" moth balls, which claim to be 99.95% napthalene. I've never used them for any higher purpose, however.
https://www.wegmans.com/webapp/wcs/stores/servlet/ProductDis... roductDisplay
[Edited on 8-6-2010 by Magpie]
The single most important condition for a successful synthesis is good mixing - Nicodem
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Lambda-Eyde
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Paddywhacker: I like the swastika. 
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not_important
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In SE Asia and nearby countries camphor is somewhat common, in the rest of the world you'll find naphthalene or p-dichlorobenzene.
Indians immigrating to western countries not infrequently discover that their auspicious and even holy symbol has quite different means in their new
country.
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JohnWW
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Were the Nazis into producing their own camphor as part of their war effort? I doubt it, although camphor trees are found in the parts of southeastern
China, Taiwan, and Indochina that were occupied by the Japanese for many years until the end of the war in the Pacific.
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densest
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I've seen synthetic camphor in 1-ounce packages in pharmacies (chemists' shops) in the US. It's also available mail order - there may be an extra fee
for airtight packaging! Natural camphor is harder to find and much more expensive.
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not_important
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sigh - the swastika, both deosil and widdershins, have been used for thousands of years throughout the world. It generally has connotations of good
luck, auspicious circumstances, and even holyness. The Wikipedia article is fairly accurate, I'd suggest reading it.
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Sedit
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I concure with N_I. The swastika is a symbol of good luck and good fortune. People that associate it with Nazi know very little about the most
important symbol in the history of the earth. It is the ONLY symbol that spanded every continent even when they where not suppose to have contact with
each other. Those who dispise it need to learn more about it and see that it could rewrite history as we know it if more study was done. The nazis
didn't chose that symbol by chance alone and like it or not Goodluck and prosperity did have a habit of following them around....
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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peach
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I'm going to make some assumptions about why you might be interested in these reductions and camphor.
Firstly, the type of material you're after for "those reactions" is called dark camphor, and it's not sold due to it being carcinogenic. If you want
camphor for something more legal, you can buy refined bottles of it for not a lot of money.
There also other methods for producing "those amines" that don't involve amalgams or borohydrides. I have read first hand accounts from people running
these methods and yielding the amines they're after. But they're "those types" of people and the posts are on "those forums".
[Edited on 12-6-2010 by peach]
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mnick12
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Well I found a source of Vanillin so I will order some of that to reduce with TUD . Though I need to look around for camphor.
When the vanillin arrives I will attempt to reduce it using TUD, and I will go ahead and post my results. I may post pictures if anyone wants. But it
may take a bit for the Vanillin to arrive.
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organometallic
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mrnick12: I would appreciate photos. This will produce the dihydroxybenzaldehyde, correct?
In vials of ivory and coloured glass
Unstoppered, lurked her strange synthetic perfumes,
Unguent, powdered, or liquid - troubled, confused
And drowned the sense in odours.
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