[Meter]

Hi.

I found this step in a synthesis of a certain compound and I determined that it looks a lot like the chlorination of a carboxylic acid. From what I can find, such chlorinations generally use SOCl2 (thionyl chloride) and not SO2Cl2 (sulfuryl chloride). What makes this different?

[rolnor]

It looks strange, DMF can probably not be the solvent? Maybe its a type-error, it should be SOCl2? Also you will get the product as HCl-salt.

[Meter]

It looks strange, DMF can probably not be the solvent? Maybe its a type-error, it should be SOCl2? Also you will get the product as HCl-salt.

I just realized that the article in which I found the synthesis, they do not cite a source for its synthesis pathway. Wikipedia isn't always a great source, so it could just be nonsense.

[AWK]

If this diagram is from Wikipedia, there is sure to be a link citing the original publication there. Printing errors can happen anywhere.
Once you notice an error, you can correct it yourself after thoroughly checking the reference literature.

DMF is commonly used as a catalyst in the synthesis of acid chlorides with thionyl chloride.

[rolnor]

I think DMF is used as catalyst when oxalyl chloride is used,  not thionyl chloride. It is not used as solvent?

[Meter]

If this diagram is from Wikipedia, there is sure to be a link citing the original publication there. Printing errors can happen anywhere.
Once you notice an error, you can correct it yourself after thoroughly checking the reference literature.

DMF is commonly used as a catalyst in the synthesis of acid chlorides with thionyl chloride.

It doesn't seem like there is a paper attached to it.

[Babcock_Hall]

A slightly tangential comment: It has been some time since I worked with SO₂Cl₂, but I used to distill it away from a lower boiling impurity shortly before use.

[wildfyr]

DMF is perfectly fine to be a solvent. Why wouldn't it be? I'm more concerned about that amine there either reacting with the acid chloride or this thing precipitating out when protonated.

BTW its common to run chlorinations in neat thionyl chloride, sometimes with a drop of catalytic DMF.

Workup is either distill off thionyl chloride, or if the product is kinda water stable, dump it into ice then extract with water and organic solvent.

[rolnor]

Wildfyr, I think acid chlorides react with DMF much like POCl3 does when you make Wilsmeyers reagent.
I have never seen DMF used as catalyst when making acid chlorides with SOCl2 but often when oxalyl chloride is used.

[wildfyr]

Hm... I think i've used those conditions for SO3Na --->SO2Cl

[rolnor]

Wildfyr,I can be wrong, I dont have any reference to support this, its more from experience.

[AWK]

US1326040A - 1919

[rolnor]

AWK, what does the patent say, I can not find it on the web?

[AWK]

https://patents.google.com/patent/US1326040A/en

[rolnor]

Thanks AWK. I dont  see anything about DMF but its a lot if text, have I missed it?