Sciencemadness Discussion Board

Oxalyl Chloride Challenge

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Keras - 9-7-2022 at 02:39

Did anyone try the method, described in a Chemplayer’s video, of making acyl chlorides by passing dry HCl into an ice-chilled mixture of acetonitrile and said carboxylic acid (in this case, oxalic acid)?

ErgoloidMesylate - 19-8-2022 at 10:13

Quote: Originally posted by Praxichys  
Well, beans. Back to the drawing board.


Incredible.

ErgoloidMesylate - 19-8-2022 at 10:23

Quote: Originally posted by Keras  
Did anyone try the method, described in a Chemplayer’s video, of making acyl chlorides by passing dry HCl into an ice-chilled mixture of acetonitrile and said carboxylic acid (in this case, oxalic acid)?


Looks to me like the only sure way of doing it is with phosphorus pentachloride, sorry.

Niklas - 3-12-2023 at 23:55

Are there any sources where DMF where would be accessible as an otc chemical? Since if there are, one possible way would be to chlorinate oxalic acid using a mixture of DMF and TCCA, forming a Vilsmeier-reagent in situ [1][2].

[1] https://pubs.acs.org/doi/10.1021/acs.joc.1c00334
[2] https://www.thieme-connect.com/products/ejournals/pdf/10.105...

Lionel Spanner - 8-12-2023 at 18:14

Quote: Originally posted by Niklas  
Are there any sources where DMF where would be accessible as an otc chemical? Since if there are, one possible way would be to chlorinate oxalic acid using a mixture of DMF and TCCA, forming a Vilsmeier-reagent in situ [1][2].

[1] https://pubs.acs.org/doi/10.1021/acs.joc.1c00334
[2] https://www.thieme-connect.com/products/ejournals/pdf/10.105...

Laboratoriumdiscounter, based in the Netherlands, sell it as a stock item at €15 for a litre.

Niklas - 8-12-2023 at 23:28

Quote: Originally posted by Lionel Spanner  
Laboratoriumdiscounter, based in the Netherlands, sell it as a stock item at €15 for a litre.


Yeah, right, somehow completely forgot about them, and that even though my DMF actually is from there lol

Keras - 9-12-2023 at 00:07

Quote: Originally posted by ErgoloidMesylate  
Quote: Originally posted by Keras  
Did anyone try the method, described in a Chemplayer’s video, of making acyl chlorides by passing dry HCl into an ice-chilled mixture of acetonitrile and said carboxylic acid (in this case, oxalic acid)?


Looks to me like the only sure way of doing it is with phosphorus pentachloride, sorry.


Someone (I’ll do it if I have time) should try using triphosgene. Apparently, it can be conveniently synthesised from dimethylcarbonate. See the famous book Small Scale Synthesis of Laboratory Reagents.



Screenshot 2023-12-09 at 09.07.05.png - 269kB

[Edited on 9-12-2023 by Keras]

EF2000 - 9-12-2023 at 09:44

If you want to try it, take care. Triphosgene is often branded as "safe phosgene", but recent paper in OP R&D says that it's not much safer.
Triphosgene have relatively low vapor pressure. Alas, it's still enough to build up a dangerous concentration and gas you:
Quote:

At room temperature, the [triphosgene] concentration of a saturated atmosphere is 4.2 g/m3, approximately 100 times higher than the LC50 value for rats (41.5 mg/m3)

Vapors also have trouble reacting with water, so they can pass through scrubber. Both thermal decomposition and off-gassing during reactions produce phosgene gas (thus violating rule 3).
As cherry on top of this Flanders pie is that there is no available detector for triphosgene.
Edit: on further reading, it's even scarier: "After an acute toxic effect, a second mortality peak occurs after 11–14 days." Top grade realistic Osowiec fortress experience.

[Edited on 9-12-2023 by EF2000]

Keras - 10-12-2023 at 03:44

Quote: Originally posted by EF2000  
If you want to try it, take care. Triphosgene is often branded as "safe phosgene", but recent paper in OP R&D says that it's not much safer.


Right, I didn't pretend it was innocuous. In any case, I always work outside, so that limits the risk.

But duly noted, really. That’s not ironical.
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