Is my synthesis procedure of Mephedron right?

[Brambus]

Hello everybody, i have been working on the following procedure hoping a good chemist will read it and give me a note when it is incorrect thank you!

Synthesis procedure

1. 2-Bromo-4'-methylpropiophenone 100g is poured into the reaction vessel.

2. DMF 400mL is poured into the flask. Top stirrer is turned on and the reaction mixture is heated up to 40 °С.

3. When temperature is reached 40 °С, methylamine HCL 80 mL is poured into the reaction mixture and stirred for 20 min.

4. 20 min have passed. Next, distilled cold water 1 L (Room temperature) is poured into reaction mixture and stirred for few minutes.

5. Ethyl acetate (EA) 500ml is poured into the cylinder. Stir for 1 a 2 minutes.

6. Than, the stirrer is stopped, the mixture is divided into two layers.

7. The upper base extract with EA is poured into a beaker.

8. Anhydrous acetone 500 mL is added to the reaction mixture and hydrochloric acid (HCl 48%) is added dropwise (in the drip funnel) (for further crystallization) with a constant stirring to reach pH 4-5.

9. Let the mixture precipitate.

10. Then the mixture is put in a freezer for at least 24h for better crystallization.

11. Mephedrone is filtered using vacuum.

12. Product is rinsed with cold acetone until white.

13. After drying, IPA(isopropyl alcohol)+ water solution (30:70) is poured.

14. The product is left for a few days for recrystallization.

 

[Osmosis Vanderwaal]

I just checked the pH of 2-b-4-mp. 5.5 I don't think that is going to deprotonate the HCL on the methylammonium chloride. I'm not a chemist but doesn't this rxn with CH³NH²HCL require NaOH or another strong base to liberate the methylamine? 48% HCL seems awfully hot to use directly , it's 13mol I calculated (/L). Methylamine HCL is a solid, so 80ml is awfully ambiguous. 80ml of what mol. Strength? I haven't looked up the solvency but I know that methylamine gas can only reach 50% w/w in water

 

[Brambus]

Thank you for your reply, good points and also good to know that methylamine gas can only reach 50% w/w in water i was just working on something related!

 

[Berlin777]

how have you acquired HCl 48%?

 

[Brambus]

A supplier of mine in poland can get it, but i will go with the recommendations and go for a lower percentage anyway.

 

[PersonVPN]

1) Bro !) Methylamine hydrochloride and 40% aqueous solution of methylamine are completely different substances!
Therefore, according to your scheme, nothing will work out for you!
This site has a detailed video on how to do it right

Mephedrone synthesis

Mephedrone synthesis from 2-iodo-4'-methylpropiophenone (CAS 236117-38-7) with ethyl acetate https://bbgate.com/threads/mephedrone-4-mmc-synthesis-from-haloketone-in-ethyl-acetate-1-10-kg-scale.39/

bbgate.com

2) I have never seen hydrochloric acid 48% before
48% There is hydrobromic acid, But she's expensive. 37% is enough for you.
3) Study the video carefully. It will help you avoid many mistakes.
4) DMF very, very, toxic and has a strong effect on the heart! Better take it DMSO ! In addition, it is available for free sale

I hope I helped you at least a little!

 

[Brambus]

You definently did thank you bro!

 

[spongebomb]

@PersonVPN
at point 4) the quantities remain the same with DMSO (as with NMP, for example) ?

 

[PersonVPN]

There will be no difference in the reaction, even if you take 200-300 or 400 ml (DMSO; NMP )
Simply due to the smaller volume, the RM will heat up more! And you will have to cool more intensively.
I strongly do not recommend pouring the entire solution of aqueous methylamine into the mixture of solvent and ketone at once!
At the beginning, add no more than 20% methylamine to RM.
Otherwise, you will get a sad experience and a cleanup of the workplace.
WARNING !!!
ATTENTION !

Do not conduct experiments with bromination or BK4 in a residential area!!!
Otherwise, lachrimators will remind you of themselves for a long time

 

[Berlin777]

3. it should be either 200mL MA 40% or 150g MA HCl

 

[PersonVPN]

I think that TS simply does not understand the difference between a 40% aqueous solution of MA, and MA HCL (hydrochloride)
Perhaps the following link will help him understand the difference:

Methylamine Freebase Solution Preparation

Introduction This post is written with a purpose to explain how to prepare methylamine freebase aqueous (cas 74-89-5) and methanol (cas 74-89-5) solution with known concentration from methylamine hydrochloride (cas 593-51-1) from. This issue is frequently met by customers around EU and other...

bbgate.com

 

[Berlin777]

Or he could just simply follow my method which is posted on the forum instead of complicating

 

[Brambus]

@Berlin777 I am very interested in your method but i couldnt find your method, could you share the link for me??

 

[Berlin777]

http://bbzzzsvqcrqtki6umym6itiixfhni37ybtt7mkbjyxn2pgllzxf2qgyd.onion/threads/4-mmc-synthesis.9187/

I don't know why but the page won't load
first you need to prepare NaOH solution, 100g dissolved in 200mL water, wait until it cools down then add to the flask with your dissolved ketone, then start adding MA HCl in small batches to maintain temperature in right range

 

[Brambus]

Thank you, that sounds straight forward and practical! I think the quantities you used of NAOH and water are for 1kg of 2B4M? And you do this process during the synthesis in the reaction vessel, if i understand correctly?

 

[Berlin777]

Here are the proportions I use:
BK4 - NaOH 1:1
BK4 - MA HCl 1:1.5
NaOH - H2O 1:2
BK4 - DCM 1:3