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Author: Subject: Various chlorotoluenes produced during Toluene+TCCA+uv synthesis
Newton2.0
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[*] posted on 8-3-2021 at 13:52
Various chlorotoluenes produced during Toluene+TCCA+uv synthesis


I have variety of fractions obtained from the chlorination of toluene using TCCA and I'm trying to figure out how to classify them.

My pitiful brute force search comparisons of chlorinated toluenes against their boiling points between 150-205C have only yielded:

ortho/meta/para-chlorotoluenes 159-162C
benzyl chloride 179C
benzal chloride 205C

Di-/tri-substituted chlorides are too-high boiling to fall in this range. And I'm not really interested in polymerized chlorotoluenes or the miscellaneous organic nonsense that's going to be present. Chemistry is messy.


Shall I assume the these values are, in practice, "blurred" due to my use of only a 300mm vigreaux column and imprecise temp monitoring. As in, the bp of a relatively pure fraction of benzyl chloride might really end up falling in a range from 177C-182C?

Let me know what your thoughts are, please! :D
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RustyShackleford
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[*] posted on 8-3-2021 at 14:11


My experience w that reaction was that it almost only formed benzyl chloride, did you add something like FeCl3 to form the ring substituted toluenes?
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Metacelsus
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[*] posted on 8-3-2021 at 15:09


Reaction with Cl2 will mostly form benzyl chloride, by radical halogenation. I'm not sure about TCCA though, since it probably doesn't form radicals as easily as Cl2 does.

Can you provide more info about your reaction conditions?




As below, so above.
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Newton2.0
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[*] posted on 9-3-2021 at 09:17


200g TCCA is added over a period of three days to a 3-neck 1L RBF containing 425mL toluene. Then a UV-C light intended for hand sanitization is applied to the side of the RBF and a halogen lamp (no specs) is used on the opposite side.

At some point there was a runaway thermal issue which caused a portion of the solid to polymerize and tar. The reaction was left to run for a total of six days and filtered on a Büchner funnel.

Then I set up for fractional distillation with a 300mm vigreaux column. I obtained a huge amount of liquid between 150 and 200C which leads me to wonder if I made additional products. Radical mechanisms might have created something different.

However, if I made almost exclusively BzCl, that would be fantastic!
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Newton2.0
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[*] posted on 25-3-2021 at 10:27


I recognize now that the way I would get ring-substituted chlorine is with the addition of FeCl3 and then separating later. Thanks!

What I have is most likely BzCl and toluene and miscellaneous junk from the TCCA breakdown products. I kept everything that came over between 175-185C and redistilled to about approximately 62mL of relatively clean BzCl. It has been stored in amber bottles, however, I expect the shelf life is terrible.
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egret
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[*] posted on 25-3-2021 at 14:11


Benzyl chloride can be stabilised by aqueous sodium carbonate. I tried it and it works. The benzylchloride is siting on the shelve 9 months without visible degradation. I thing it was discussed here in the forum but I can´t find it.

Google patent
https://patents.google.com/patent/US2542216A/en

"Benzyl chloride is presently stabilized with a 10% aqueous sodium carbonate solution. Benzyl chloride thus stabilized may be safely shipped in black iron drums without danger of decomposition in the event of accidental contamination with iron, rust or iron salts. For example, 450 pounds of benzyl chloride mixed with 23 pounds of a 10% aqueous sodium carbonate solution may be safely shipped in a gallon black iron drum. This wet stabilized material is a milky-white emulsion, from which a water layer may separate upon standing. However, before use, the benzyl chloride must be recovered from the stabilized solution, as anhydrous liquid benzyl chloride is preferred and necessary for most operations."

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Newton2.0
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[*] posted on 12-4-2021 at 11:28


Excellent! This is a great find! I appreciate this very much. I will make sure to add the appropriate amount to stabilize and then reclaim the BzCl when it's needed.
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[*] posted on 15-4-2021 at 17:35


Might be easier to make it from Benzyl Alcohol.

Of note, the reaction produces several products. Benzyl Chloride, Benzyl Dichloride, Benzyl Trichloride.

On hydrolysis those products produce respectively: Benzyl Alcohol, Benzaldehyde, and Benzoic Acid.

Nasty stuff, Benzyl Chloride. Serious Lacrimator.

I can buy Benzyl Alcohol by the gallon, cheap. Same goes for Benzoic Acid. Benzaldehyde, not so much. Hard to acquire, in a lot of jurisdictions.

If you have a hankering for Acid Chlorides, like Acetyl Chloride Etc... Benzaldehyde can take you there. It can react with Cl2 to form Benzoyl Chloride, by which other Acid Chlorides may be synthesized.

[Edited on 16-4-2021 by zed]

[Edited on 16-4-2021 by zed]

[Edited on 16-4-2021 by zed]
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Newton2.0
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[*] posted on 18-4-2021 at 11:47


As a matter of fact, I do have my eyes set on a few acid chlorides, namely propionyl chloride and butyryl chloride. I was just going to go the PCl5 route. But benzyl alcohol is way cheaper.
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