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

[William Dampier]

Reaction scheme:

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Reagents:
Propionyl chloride - 1000 g,
Toluene - 3000 ml,
AlCl3 anhydrous - 1500 g.

Equipment:
Flask,
Reflux condenser,
Drip funnel,
Distiller (straight condenser),
Mechanical stirrer.

All parts of the device must be carefully dried. Toluene applies anhydrous and taken in excess, as it serves as a solvent.

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Synthesis of 4'-methylpropiophenone. Friedel-Crafts reaction.

• G.Patton
• Jan 31, 2025
• 11
• 4'-methylpropiophenone synthesis 4-mmc precursor friedel-crafts reaction

Source: ChamPlayer channel

Thanks @CARLITOBRO for sharing

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Synthesis:
1. In flask, equipped with a reflux condenser, a calcium chloride drying tube, drip funnel and mechanical stirrer, place aluminum chloride and toluene.
2. Start stirring and was added dropwise propionyl chloride with such speed, to the uniform release of hydrogen chloride.
3. In the case of a rapid reaction, outer cooling is needed.
4. The end of the reaction is determined by the cessation of hydrogen chloride.
5. After completion of the reaction, the reaction mixture was poured onto crushed ice and add a diluted hydrochloric acid solution to dissolve the aluminum hydroxide precipitate.
6. The top, benzene layer separated from the lower, water layer.
7. From the aqueous layer extracted with 4-methylpropiophenone with a small amount of benzene.
8. Benzene solutions are condensed and washed with a dilute solution of sodium hydroxide, water and dried magnesium or sodium sulfate.
9. After the toluene is distilled off to get 4-methylpropiophenone (bp 239 *С).

 

[Oxygen]

There was a alternative for mechanical stirrer?

 

[AgamemnonFromTroy]

One Alternative would be strong magnetic stirrer although the large ones are pretty pricy and it would be more cost effective to buy a mechanical one.

 

[Hans-Dietrich]

For example, what is the alternative ??? The volume of the reaction mass is approximately 5.5 liters, then the reactor is at least twice as large. Substances are extremely aggressive. I don't see any alternative. It is necessary to use a reactor (stainles steel) with a mechanical stirrer and a flue gas for synthesis. Protective suit (full body) with boots and gloves and a gas mask (complete head). It is also necessary to take into account the large amount of heat generated during the reaction.

 

[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

 

[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

 

[amieri]

"let me show you something"

 

[Tony]

Can you please make a video for synthesis , it will help me to synthesis mephedron , and it will help all beginners to make a mephedrone , it will be the most important video for me to make a mephedrone , because in my country i didn't find it to buy ( methylpropiopenone) so i have to synthesis it , and sorry for my English , i am from Egypt , my greetings @William Dampier

 

[Netflix]

Buy 2b4m is legal in poland and is cheap

 

[Tony]

I am from Egypt , its unfortunately unlegal to buy it , It is forbidden to sell in Egypt...Can you help me somehow?

 

[hlebsladky2]

What's the possible yield?

 

[G.Patton]

90-95%

 

[estimated]

hello, can toluene be replaced with xylene?

 

[plancklong]

No. The toluene is not just the solvent. It is the basis for the 4-methylpropiophenone:

Which xylene did you have in mind, o, m, or p? Never mind, it's probably a mixture of all 3:

If you did use these, can you see that you would NOT be synthesizing 4-methylpropiophenone?

 

[AgamemnonFromTroy]

You could synthesise toluene from xylene by hydrogenation although toluene is pretty easy to source therefore doing this isn’t that practical.

 

[G.Patton]

Probably yes

 

[reza]

After the completion of the reaction, the reaction mixture was poured onto crushed ice and diluted hydrochloric acid solution was added to dissolve the precipitate of aluminum hydroxide. Step five is a bit
Could you please explain more, do you mean to put the container of the reaction mixture in a container of ice? How much concentrated hydrochloric acid?

 

[UWe9o12jkied91d]

The reaction mixture itself, not the container.The ice water will help dissolve soluble impurities aswell as cool down the exotherm from HCl reacting with aluminium compounds.
Dosent matter much as to my interpretation, it is done to dissolve the aluminium residues, which can create a gunk at the interface that is hard to separate fully.Add until residues are dissolved and I think you can use any conc. HCl, taking care if adding conc., that’s all.

 

[Osmosis Vanderwaal]

Man! If anyone know a source or easy synth for propoinyl chloride?

 

[UWe9o12jkied91d]

I can ship that to USA if you are interested, I've gotten a lot of naughty things in the US.

 

[Osmosis Vanderwaal]

Spoiler: 🤔🤔🤔

 

[Lev]

Good afternoon friends.Please tell me where I can watch the video tutorial for the synthesis of 4-methylpropiophenone ?

 

[reza]

Is distillation in a vacuum meant? I don't have a rotary evaporator, do I need one?

 

[UWe9o12jkied91d]

4-methyl propiophenone is somewhat stable in air as far as I know, so you could let the toluene just evaporate if you wanted to

 

[reza]

Does it mean I don't heat? Don't you think it will take a long time to completely evaporate?
Thank you for your opinion and advice

 

[UWe9o12jkied91d]

Yes, it's possible, toluene evaporates quite fast even at RT.
You can also heat gently on a water bath