Synthesis of 4'-methylpropiophenone from toluene by Friedel-Crafts reaction (1kg+ scale)

[Deedubbau]

Mr. Safety to the rescue....

Yeah you better make sure you are wearing all that protective gear. Cause if you take this advise and use stainless steel you are going to have a disaster on your hands. Stainless is rapidly attacked by organic acids, and chlorides. So once you warm this mix up you better be prepared to run....or just stick with glass

 

[amieri]

"let me show you something"

 

[The-Hive]

I use stainless steel vessel for larger reactions so far so good IMO

 

[waltjr5858]

Yeah but for this exact reaction we're talking you're doing something extremely dangerous using metal. You don't need all that crap and first of all just because they're doing a large reaction doesn't mean someone else is the mechanical steerer is absolutely not needed and a stir bar is perfectly fine. Use glass only for anything to do with acids. You also don't need all that gear. Little out of control looking like you're cleaning up radioactive spill.

 

[waltjr5858]

You should actually probably delete that comment somehow or a mod should because if anyone reads that and does it they're actually putting themselves in danger. Anyone that deals with chemistry on a normal basis should absolutely know that you wouldn't use a stainless steel reaction vessel for that I actually kind of laughed a little bit

 

[NovicechemistEU]

Tomorrow I'm starting the big day synthesis with a small batch.
I wanted to start with a small batch for my first try.
1.08 mol 100 Gr 95.2 mL propionyl chloride
1.12 mol 150 Gr: AlCl₃
2.81 mol 300 ml 261 Gr Toluene
I can use 50 ml more toluene. 350 ml
Toluene of 99.5% purity was dried and then distilled under vacuum. We follow the advice of the masters

 

[William Dampier]

Do not forget to pour it into cold water. Not water into the reaction mixture. This is very important.

 

[Smokesalot99]

Can you replace propionyl chloride with propionic anhydride for reaction?

 

[The-Hive]

try it and let us no do it on a small scale then compare it to using propionyl chloride

 

[William Dampier]

Do you think this reagent is more easy to buy? And cheaper? I think this is not so, but if you have it, you can go with such a route but with correction.

 

[NovicechemistEU]

I finally managed to make the synthesis, I can't thank @William D. enough for helping me every step of the way, I am very grateful
Now I just need to distill the dirty 4'-methylpropiophenone under vacuum

 

[Jack]

Here's a paper on the synthesis of 4 methyl propiophenone with AlCl3 and propionic anhydride with includes a procedure https://www.pismin.com/10.1248/cpb1953.4.182 . Studies on the Syntheses of Ring Substituted p-Alkylephedrines and p-Alkylnorephedrines. Pharmaceutical Bulletin, 4(3), 182–188. (1956)

 

[Jack]

Propionic anhydride is a better acylating agent since for an amateur to obtain a acid chloride without phosphorus chlorinating agents would involve going through carboxylic acid anhydrides anyway.