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clearly_not_atara
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[*] posted on 4-6-2019 at 14:48


Anyone have any references discussing the Lucas reagent and other acidic Sn2 reactions on vicinal diols?

In particular, I’m interested in the practicality of converting propylene glycol into 2-chloro-1-propanol. The secondary alcohol should be substituted faster than the primary, but I don’t know if there are any side reactions to worry about.

Incidentally, while researching this transformation, I was unable to find any references discussing the conversion of ethylene glycol to 1,2-dichloroethane, even though this transformation is commonly suggested as a route to DCE.




[Edited on 04-20-1969 by clearly_not_atara]
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Abromination
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[*] posted on 14-6-2019 at 14:42


Anyone have any suggestions on paints they have found chemically resistant? I am painting my fumehood soon.
Much appreciated




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Pumukli
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[*] posted on 27-6-2019 at 11:20
TLC Quiz


It seems that after a lot of struggle I could finaly prepare that nicotinonitrile I asked about months ago.

I ran the starting niacinamide and the crude product side by side on a tlc plate (Kieselgel on aluminum) in 6:14 denatured EtOH : Chloroform. They each gave one spot only.

I'm curious who would guess the resulting Rf values most accurately?! ;)

This "challenge" is open for a few days then I'll announce the results!

Anyone for a ride?
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Abromination
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[*] posted on 26-7-2019 at 18:01


According to pubchem.gov, 2 ethylhexanol is a brown liquid, however various images of the substance show it to be clear. Which one is it? I feel like the images are just showing a generic liquid in a flask.
Here is an example:


38B2D701-D086-47E5-93FF-FF9C9E578ED0.jpeg - 25kB




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Pumukli
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[*] posted on 26-7-2019 at 20:01


2-ethylhexanol why should it be brown? It is a simple aliphatic alcohol of which the C-chain isn't too complicated (no conjugated double or triple bonds) so there are no chromofors.
I imagine it should look exactly like 1-octanol, maybe slightly more viscous.
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Herr Haber
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[*] posted on 29-7-2019 at 03:41


Quote: Originally posted by Abromination  
Anyone have any suggestions on paints they have found chemically resistant? I am painting my fumehood soon.
Much appreciated


I recently discovered "graffitiy proof" paints based on a fluorinated polymer that also takes advantage of a phenomenon I didnt look into.
It could be great for fumehoods.

The price was not so great though... Almost 200 Euros / liter !




The spirit of adventure was upon me. Having nitric acid and copper, I had only to learn what the words 'act upon' meant. - Ira Remsen
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Abromination
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[*] posted on 29-7-2019 at 18:06


Quote: Originally posted by Pumukli  
2-ethylhexanol why should it be brown? It is a simple aliphatic alcohol of which the C-chain isn't too complicated (no conjugated double or triple bonds) so there are no chromofors.
I imagine it should look exactly like 1-octanol, maybe slightly more viscous.

Thanks, just checking, pubchem has usually been a reliable source in the past.




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Panache
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[*] posted on 1-8-2019 at 19:32


Quote: Originally posted by bipolar  
Does acetonitrile react with sodium metal? If so, what are the products of this reaction?
I'm hoping this might be the way to make some sodium cyanide. :D


[Edited on 21-4-2019 by bipolar]


gaseous acetonitrile decomposes to HCN, a simple tube furnace (600-900C if i recall, anyway the process has 4768543983465430 references online as it is critical for fire fighters in buildings with certain types of polymers, acetonitrile became the test standard for assessing this risk) connected to a boiling flask of acetonitrile with the exiting gas stream cooled with a long air condenser then bubbled through two NaOH or KOH wash bottles, indicated to clearly show when exhausted. Clever use of three way taps will allow for changeover of the solutions.
Less safe in some respects is condensing the HCN, however it does allow one greater flexibility, ie you can weigh precise amounts out to neutralise.
Be very careful, i hear HCN has deliterious health consequences to the human organism.
Always run a lengthy test cycle at temp through your setup with compressed air or something testing for leaks.
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mayko
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[*] posted on 9-8-2019 at 08:18


So I have heard this a few places, some easily dismissed as technobabble (eg The X-Files) and others less so (Mythbusters iirc). This is that at high temperatures, the dissociation of water will create hydrogen and oxygen, which will then go on to fuel and augment the fire.

Am I completely missing something??? Isn't the whole point of their dissociation at high temperature that their combination is unfavorable? Isn't any energy released by their eventual combustion energy that the flame had previously lost? Is there some sort of potential energy transport effect I'm neglecting?




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