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teodor
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I remeber one more point why I don't like permanganate. When its reduction is started it doesn't depend on the rate of your organic product oxidation.
It just don't stop untill all permanganate is reduced (not because of the organic oxidation). I believe with CrO3 you can see the actual rate of your
compound oxidation (the change of the color).
You can easily get any (di) chromate from CrO3 in situ, but CrO3 is not always a substitution for dichromate for acetic acid solvent because it
doesn't dissolve in AcOH as good as dichromate. So you have to mix NaOH with it in a small quantity of water before AcOH addition in this case.
[Edited on 2-12-2024 by teodor]
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Keras
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I have no personal grudge with permanganate. Is just that it is difficult to source because it’s listed as a drug precursor over here in the EU. So
you have to make it yourself from manganese oxide by the fusion process, which takes time.
[Edited on 3-12-2024 by Keras]
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wg48temp9
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Quote: Originally posted by Keras  | | I have no personal grudge with permanganate. Is just that it is difficult to source because it’s listed as a drug precursor over here in the EU. So
you have to make it yourself from manganese oxide by the fusion process, which takes time. |
In the UK it is sold on eBay, Amazon, APC Pure and several other sites.
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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teodor
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| Quote: Originally posted by Keras | I have no personal grudge with permanganate. Is just that it is difficult to source because it’s listed as a drug precursor over here in the EU. So
you have to make it yourself from manganese oxide by the fusion process, which takes time.
[Edited on 3-12-2024 by Keras] |
But you need it in the form of solution. So, you can try to use manganese sulfate + ammonium persulfate (as you planned) + silver nitrate to generate
it in situ during the synthesis.
Check this thread: https://www.sciencemadness.org/talk/viewthread.php?tid=15996...
Because the synthesis will consume the permanganate there is a chance it will go to completion.
Also the rate of permanganate generation can change the synthesis, but probably it would be interesting to try. As I said, the problem with
permanganate is that it can be reduced faster than the organic compound to be oxidised.
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Keras
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Lol, turns out I might’ve made manganese sulphate inadvertently. During my last experiment with naphthalene and potassium permanganate, I collected
the cake obtained after reaction and filtration, which contains mainly manganese oxide, and added in it sodium hydrosulphite. It immediately cleared
up and I’m now with a beaker full of a whitish powder in water. That might be it. I’ll filter it tomorrow and see.
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Texium
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While this isn’t exactly in the spirit of the thread, why don’t you just buy phthalic anhydride from a chemical supplier? S3 Chemicals has 500 g
for 27 €. That seems very reasonable as you would need kilos of permanganate and a bucket scale setup to make that much.
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Keras
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| Quote: Originally posted by Texium | | While this isn’t exactly in the spirit of the thread, why don’t you just buy phthalic anhydride from a chemical supplier? S3 Chemicals has 500 g
for 27 €. That seems very reasonable as you would need kilos of permanganate and a bucket scale setup to make that much. |
Might be a good idea. It’s 57 € here which, for a commodity chemical produced at multi-ton scale, always seemed to me excessive.
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Texium
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Yeah, that is a little steep. Commodity chemical or not, selling it packaged as a lab reagent with a guaranteed level of purity will inevitably result
in a markup. S3’s price at least seems reasonable in that context. I’m selling phthalic anhydride from Aldrich 500 g for $25, but the shipping to
Europe would almost certainly make it a worse deal.
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Boffis
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Which country is Laboratorium Discounter based in? There web site is a bit obscure.
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teodor
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The Netherlands. But it is not the seller I can recommend, we have a separate thread where some people already shared their negative experience with
them.
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woelen
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Last week I again ordered some chemicals from Laboratoriumdiscounter. I ordered a small amount of 98% hydrazine hydrate and sodium peroxodisulfate
from them. I received the chemicals a few days later. My experiences with this company are quite good, but indeed, sometimes things go less smooth. My
previous order took several weeks, because their supplier took a long time to deliver the chemical to them. In my experience, it is more a matter of
communication (or the lack of communication) than wrong intent. I already told them this and wrote that on a review site (Trustpilot) as well.
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teodor
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| Quote: Originally posted by woelen | | Last week I again ordered some chemicals from Laboratoriumdiscounter. I ordered a small amount of 98% hydrazine hydrate and sodium peroxodisulfate
from them. I received the chemicals a few days later. My experiences with this company are quite good, but indeed, sometimes things go less smooth. My
previous order took several weeks, because their supplier took a long time to deliver the chemical to them. In my experience, it is more a matter of
communication (or the lack of communication) than wrong intent. I already told them this and wrote that on a review site (Trustpilot) as well.
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I really appretiate your effort to provide the constructive feedback for them. I am really glad if they are going to improve their way of business and
are reading the feedbacks for that purpose. Yes, I know that they probably have no bad intentions, but at the present time this seller is the last one
I can even consider when buying chemicals and glassware. As for the component in question I would better by some phthalic anhydride from S3.
The day before yesterday I've ordered potassium and ammonium persulfate from labshop.nl as well as some laboratory consumables. Yesterday it was
delivered exceptionally well packed. So, I am not always prefer german companies, you see.
[Edited on 12-12-2024 by teodor]
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Keras
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I’m used to ordering many items from LD and, yes, they are a bit messy, but I suppose this is just the result of their supply chain being
unreliable. Last time I enquired about a late delivery, they told me they weren't surprised the supplier they had to source the item from was late, it
was apparently usual. Then they did go great length to assuage this, they sent my items on the fly as they received it, which ended up meaning three
parcels instead of just one (and I paid no extra fees, they assumed the extra two shippings cost).
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