Boffis - 17-4-2020 at 04:48
Thiourea dioxide is used as a power reducing agent in vat dying. It functions as a reducing agent in alkaline solution but what are the oxidation
products?
mackolol - 17-4-2020 at 05:18
I have nice paper. There are a lot informations of TUDO reductions as well as whole reduction reaction with ketone.
So it seems that oxidation product in this case is SO3 2- anion and urea.
Attachment: sdarticle.pdf (166kB)
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[Edited on 17-4-2020 by mackolol]
mackolol - 17-4-2020 at 05:22
And in this paper, there is shown more specific reaction of just TUDO with base which forms strongly reducing SO2 2- ion.
I'm very interested in TUDO's reducing properties, as it is cheap and easily available and seems quite strong and useful, but all I managed to do yet
is reduction of nitrophthalhydrazide to luminol, and reduction of little p-nitrobenzene to toluidine, which i haven't isolated.
What pretty sucks about TUDO is that you need very big quantity of it compared to compound that you're reducing.
Attachment: Study on reduction of organic compounds with thiourea dioxide .pdf (308kB)
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mayko - 17-4-2020 at 06:03
Peep this thread:
https://www.sciencemadness.org/whisper/viewthread.php?tid=11...
Boffis - 17-4-2020 at 06:32
Thanks Mackolol, I haven't tried this reducing agent yet but given that it is now more accessible than sodium dithionite I think it is worth giving it
a twirl. But I didn't know what the actual reducing species was so it was difficult to design an experiment. I might try it out on some things I have
reduced with sodium dithionite (like sorbic acid) to see how it compares.
clearly_not_atara - 17-4-2020 at 08:17
In particular, thiourea dioxide is soluble in alcohols, as I recall.
That should make it much easier to reduce the esters of the dienoic acids that are attacked by sodium dithionite, which allows using this reaction on
substrates whose sodium salts are not very soluble in water. Likewise other water-insoluble substrates may become available to reduction by this
system.
Just a guess :p
edit: one example in ethanol is here: https://onlinelibrary.wiley.com/doi/abs/10.1002/jccs.1974000...
[Edited on 17-4-2020 by clearly_not_atara]
chemplayer... - 17-4-2020 at 23:48
We tried this - frisky little reaction!
https://www.bitchute.com/video/6DY4AjFTer4v/
Found it to be relatively insoluble in alcohols but soluble in alkaline solution. We figured it might be an oxidising agent but it didn't pass the
'red phosphorus' test so if it's reducing then that would be even more interesting...