4-MMC (mephedrone) synthesis in DCM

[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?

 

[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.

 

[experimentsci]

Hallo guys,
I also prefer method in DCM.
I mixed 100g of Bromketon in 300ml DCM and slowly added 200ml of Methylamin 40%a.q. solution.

Now my question, what temperature and what time would be the best.
Last time I kept temperature at 36 - 37 degrees and reaction-time was 3hours.
But the product was extremly blue after acification.

How can I repair the relation between temperature and cooking time best.
Smaller temperature = longer reaction time?

Which temperature are not working.

Can anybody help and explain the reasons of temperature and cooking time?

Thank you a lot.

 

[w2x3f5]

You have a problem with bromoketone, most likely it is dirty. you need to watch its melting point and try to recrystallize the bromoketone, or you will have aniline homologues mixed with mmc

 

[TheVacuumGuy]

My experience is that you can easily do it at 40 (rm temp! Use glass thermometer which goes into your mixture). DCM seems very reluctant to start actually boiling (like it has some buffer zone of sorts). If I increase temp it stubbornly keeps sitting at 40.

Either way. That relation time/temp thing is only important for those in a constant hurry. The fact that a reaction takes a certain time doesn't mean you need to stopwatch tightly. Product doesn't walk away. On 35 overnight, 25 overnight, 40 in 2 hours, 40 in 8 hours . you'll get the same output (where, imho, longer = better).

 

[TheVacuumGuy]

Afaik methylamine is added in quadruple excess (foolproof). It depends on the conditions. High temps, rapid stirring, open vessel, ensures a lot of it evaporates (which is not what we want).

I roughly use x 1.5

It's actually a matter of just trying and find the optimal variables as you go . There are too much for a "one size fits all".

Last Saturday did 200g batch using 400ml ethyl acetate and 400ml methylamine. That failed heavily (twice).

as I'm typing, doing another 200g batch (image). 350ml methylamine, 500ml ethyl acetate. Never fails (for me, at least).


If I would use DCM i take 600ml DCM.

 

[TheVacuumGuy]

400g bromoketone
1000ml DCM
800ml Methylamine
39 Celsius
6 hours (unintentionally, fell asleep)
In the morning added 1000ml water.

 

[TheVacuumGuy]

It finished drying to complete dryness just now. i got 265,5 gram. Could have been higher if i actually didn't forget to wash it 3 times.


Will also get losses when crystallization to account for, so finally it will end up bit lower.

 

[TheVacuumGuy]

i just finished reacting another one, 200g, 800ml DCM, 400ml Methylamine. ~2.5h 40 celcius.
now in freezer to prepare for acidify. curious to see if it yields more and better.

 

[TheVacuumGuy]

yesterday acidified, white yellowish-hue (Cream-like), started with 500ml (freebase-in-solvent) when took it from the freezer.
Acidifying, became thick, pouring aceton made volume much larger , still thick., so sended up 2000ml still quite thick creamy like substance which looks beautiful.
I decide not for adding more acetone as, a moderate thickness keeps vacuumdistill much more clean.

This morning took it from freezer. Still the same beautiful off-white color. Took it through vacuum distill, no acetone needed ecept for rinsing the beaker of leftovers.
I used the same dish as the (400g couple of reactions above), to dry.
can't see by the eye exactly, but it looks like nearly (minus a bit) as much. will report when dry.

 

[TheVacuumGuy]

Read again

 

[TheVacuumGuy]

265,5.
The reaction I did shortly thereafter was one from 200g but used 800 dcm. This one yielded 165g. So that's around 75 percent (when accounted for some losses during crystallize). Much better than the one where used too little DCM.

So the 6 hour reaction I have to admit it didnt work as good (for future readers)

 

[HewHiSt]

Hey how can i dissolve methylamin HCl to get methylamin 40% aq. ?
I know i need to create a base (sodium hydroxyde 25%) and after add it to the methylamin but i dont know the proportions
Anyone can help me ?

 

[Throw-off]

Laboratory FAQ has a whole thread about Mole Ratios etc.

 

[spongebomb]

one question, i cant find a answer until now.
When the temperatur is so critical, why not cooling the rmx all time long ?
maybe not more than 25°C ? Hope not too silly the question

 

[Joker1944]

Your article is very valuable, thank you.
How did you make the 40% methylamine solution?
I have methylamine hci and I want to make a 40% solution.

 

[HewHiSt]

You need to create a base with a NaOH solution
There is many thread about it

 

[4synergy]

Meph in DCM

 

[TheEnthusiasticCat]

I think 300ml DCM is plenty for this amount of BK4, 500ml in my opinion is too much and you could be saving money instead.

How long does your crystallisation take out of curiosity?

Hope you're well.

 

[4synergy]

Took 1 day for me

 

[TheEnthusiasticCat]

Can I see your crystals please?

 

[4synergy]

https://imgur.com/8eJDFAB

 

[TheEnthusiasticCat]

They look nice.

So the whole solution that contained your solute and your choice/s of solvent completely crystallised in 1 day, or are these crystals taken out before the whole crystallisation had finished?

We also take around a day, but we have increased this to 36 hours and currently obtain around 600g crystals from a 1000g of BK4 synthesis, I may have a method where I can increase this even more but its untested so I can not confirm.

Very clean, good job there pal.

 

[Albert13]

Do you mean crystallization in the refrigerator?

 

[4synergy]

Yes