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Author: Subject: electrolytic chlorinations
Organikum
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shocked.gif posted on 13-2-2004 at 15:32
electrolytic chlorinations


electrodearray:



This is made from graphite rods from batteries and some glasstubing/rubbertubing and works astonishing well.
The central electrrode is the cathode where hydrogen is evolved, the outer rods serve as anodes providing a higher surface area where the substrate gets chlorinated.

Powered is the array by an old AT-PS on the 5V line.

Some pictures "in action" will follow.




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[*] posted on 13-2-2004 at 16:46


That is a thing of beauty. Can it electrolytically chlorinate acetic acid? If it can, I must build one myself! Chloroacetic acid is such a versatile starting point for so many compounds, yet requires some real technochemistry to make at home.



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Organikum
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[*] posted on 13-2-2004 at 17:51
No.


Acetic acid is not to chlorinate electrolytically (sure) and also not by chlorine directly (as far as I remember).
It is for this property widely used as solvent in electrolytic chlorinations.

no way. sorry.

The electrode array is by no way final but a quick to disassemble/reassemble experimental prototype. I actually used three different ways to fix the carbon rods, PVC-melt in, epoxide and waterglass to see what stands best.




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[*] posted on 14-2-2004 at 11:20


"Acetic acid is not to chlorinate electrolytically (sure) and also not by chlorine directly (as far as I remember)."
Actually, chloroacetic acid is obtained by catalytic chlorination fo acetic acid (the catalyst being P or S). The catalyst is used to speed up the process. Sunlight is also highly recommended, as it speeds up chlorinations. Acetic acid is susceptible to chlorinations, as the carboxyl group activates the molecule. This explanation is given by a chemistry book to explain why carboxylic acids are chlorinated directly (and a diagram of the reaction).
On the array: nice DIY mad science! I bet it's perfect for preparation of NaClO3 (at temperatures not too high to prevent erosion). A universal piece of apparatus!
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thumbup.gif posted on 23-2-2004 at 00:24


Very nice unit Orgy...For some reason it doesn't suprise me though...But again good work (as usual)
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[*] posted on 18-11-2004 at 09:19
RE: chlorination


Organikum......nice work , what is the source or chlorine for the apparatus, second will it chlorinate a primary aromatic alcohol?

What are the current requirements i.e. time , voltage, how will you test if the chlorination is done ? TLC?

This is much better than thionyl chloride, if you can get it, and those pesty Phosphorous Halides.

Again congratulations on this design and avant guard approach to al old problem......solo




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[*] posted on 24-11-2004 at 04:29


The chlorine source is the HCl which is electrolytically splitted into Hydrogen and chlorine.

This method as described is not useful for the chlorination of alcohols on the hydroxy group(s). It is even not useful for sidechainchlorinations, toluene or similar.

Alcohols require H-X (X being a halogen)and in the case of HCl some help from sulfur, phosphor or zincchloride. Alternativly very rough conditions do the trick - high temperatures and pressure.

In case the halogenation is to be done for later reduction by catalytic hydrogenation I would plead for bromine or direct reduction using perchloric acid or H2SO4 as promotor.




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