4-MMC (mephedrone) synthesis in DCM

[SonicNL]

I've tried this synthesis and gotten yields ranging from 30% 45%. Sharing in case it might be helful to others. Vice versa, other people might know changes to this synthesis for higher yields.

Improvements are always welcome

Needed:
100 g 2-bromo-4-methylpropiophenone
500 ml DCM
200 ml Methylamine 40% aqua solution
60 ml HCI 30÷ aqua solution
550 ml Acetone
2 L Deminiralised water
PH measuring Strips
1 L IPA

Equipment:
Round bottom flask 2 L
Hotplate
Measuring cups 1 L
Crystallization dish
Vacuum pump
Buchner flask

1. Add 100 g 2-bromo-4-methylpropiophenone to 500 ml DCM and let it dissolve.
2. Add 200 ml methylamine in 4 portions
3. After 30 mins, put on hotplate and stir.
4. Temperature 32-36 C for 4 hours, or 40 C for 2 hours.
5. Rinse in measuring cup with demi-water until there is no methylamine smell left. Stir or shake after adding.
6. Add an ice cold solution of acetone/HCI 550ml/60ml, or add ice cold acetone and add HCI after.
7. Measure the PH, should be 6.
7. Put the 4-MMC freebase in freezer for 12h
8. Rinse with ice cold acetone trough buchner filter.
9. If you have obtained dry 4-MMC prepare a solution of 50/50 demi-water and IPA. Add 1g per 2-3 ml solvent. Boil until 4-MMC (Not longer than needed, aprox. 1-3 min.). Pour into a crystallization dish. When crystallization stops at room temperature, put the dish in the fridge. Put in freezer after and you will be left with nice looking crystals.

 

[SonicNL]

@HerrHaber this is the method i've been using so far.

 

[SonicNL]

Wet crystal

 

[pachemguy]

That's some fine crystal you got there ican smell it threw the screen already 4mmc was to me at least never rreally popular here in the USA but a I purchased a few kgs before it got put on ban sadly gone but dearly missed. But 4mmc absolutely next on my list as soon. As I finish up the a-pvp Synth. So you purchase the bromoketone skipping the bromonatio. All together? I found a few seemingly good sources for methylpropiophenone but I could never find the 2 bromo species that would be awesome!

 

[SonicNL]

Thanks. It sure does have a smell. I was not satisfied though, so I repeated the washing and crystallization procedure.

Yes, I'm trying to avoid working with bromine. And yeah my suplier provides high quality bromoketone and they know how to ship.

 

[w2x3f5]

4 point. at 35 degrees the reaction takes place in two hours, at 40 degrees there will be more impurities. What is the yield of powder? The crystal is dirty.

 

[SonicNL]

You are wrong. Its 4 h on 35 c
Read instead of only looking at my crystal. Ur anwsers are in my posts lol.

 

[w2x3f5]

Sorry, I didn't notice the release of the substance. Now I see it frustrating 35-45.

 

[SonicNL]

@UWe9o12jkied91d is also a reliable supplier.

 

[OttoBulletproof]

In other synthesis NMP is also used. Is it not actually necessary? Will not using it reduce yields?

 

[SonicNL]

Not sure about this. This synthesis works but there might be better ways. Try it and you'll find out. This worked for me.

 

[Sailor]

@SonicNL, was wondering when you replace NMP with DCM, if it is still necessary to add benzene before letting the layers divide? Have you tested it? Also curious, if you dried the freebase over MgSO4?

Am looking into this synthesis https://bbgate.com/threads/mephedrone-synthesis-4-mmc-in-nmp-solvent-large-scale.231/ but using DCM instead of NMP, as well as ethyl acetate instead of acetone and not sure if benzene is needed or not.

 

[SonicNL]

Hey, late reply but to answer your question:
No, adding benzene is not neccessary as DCM is the solvent instead of benzene. Benzene is more carcinogenic than DCM.

I havent tried NMP and im no expert maybe someone else can answer this.

 

[Dexterror]

Why hcl 30% not 35-38 % ?

 

[UWe9o12jkied91d]

Because it works just the same and is cheaper/easier to find probably

 

[Heineken]

yes is much country is hard to found 35-38% acid

 

[Dexterror]

I can use 35-38% but use less Yeah ?

 

[UWe9o12jkied91d]

Ye, you can also find silyl chlorides to make anhydrous hcl or buy in ether or methanol.

 

[TheVacuumGuy]

Searched for this but couldn't find usable info. Could you elaborate?

 

[Dexterror]

no reflux condenser needed for this synthesis? Dcm heated to 40 degrees (boiling point) can sometimes lead to an explosion heated for such a time at such a temperature in a closed flask?

 

[UWe9o12jkied91d]

it's better praxis to use a condenser with a balloon or glove covering the exit, it's not necessary to stopper tight
I do this synthesis in DCM and use 0 heat, just good stirring and left overnight

 

[Dexterror]

But if I do this synthesis with heating to 40 degrees with a closed flask, an explosion is possible?

 

[UWe9o12jkied91d]

probable rather than possible I would say, if the whole mass is at 40C in a closed glass system
the author's probably he's just SET it to 40C without measuring the temp of the mass or maybe I'm underestimating him

 

[TheVacuumGuy]

It could be me, but read nowhere a closed flask was used. And why would you? Closed flask if pressure becomes too high the stopper will pop off nothing more nothing less

 

[TheEnthusiasticCat]

Build up of pressure if you seal completely, I would recommend having slightly ajar to prevent build up of pressure and also to contain any fumes / smells, of course extraction of some sort is recommended. I'm comfortable using a temperature between 38°C to 40°C when performing a 4MMC synthesis using DCM. Or you can do 0°C for 18 to 24 hours, 24 hours would be preferable.