Mephedrone (4-MMC) synthesis; easy to perform- high yielding

[tucoXxX]

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Introduction:

In the following, forum members will be presented with a synthesis that is very easy to perform, does not take much time, and gives an exceptionally high yield. The method is a result of many years of experience and inputs from various sources that go back to the times of the legendary Hive forum. All of them deserve high recognition and a great tribute is paid to them.​

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Reaction: ​

View attachment 13954

Reagents:

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1. 2-bromo-4'-methylpropiophenone (CAS 1451-82-7) 500 g;​

2. Methylamine 40% aq – 750ml;​

3. Hydrochloric acid (HCl 37%) appr. 250 ml;​

4. Distilled water, clean tap water;​

5. Dichloromethane 2,3l;​

6. Tetrahydrofurane, (Aceton);​

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Procedure:

1.Dichloromethane (DCM) 1.5 l is poured into the reactor/flask and a condenser is attached.​

2. 2-bromo-4'-methylpropiophenone 500 g (CAS 1451-82-7) is added.​

3. The mixture is stirred until complete amount of bromoketone is dissolved.​

4. Methylamine 40% aq, 750ml is added slowly with a drip funnel.​

6. The mixture is stirred for 2 ½ h at 38 °C. .​

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View attachment 13947

7 After that, the reaction is quenched by adding 7000ml ice cold clean tap water.

8. The mixture is stirred for 1-2 min and the DCM layer is separated off.​

9. The remaining freebase is extracted with 500 ml DCM.​

10. The combined organic layers where washed twice with 300ml water.​

11. The combined washed organic layers were acidified with 2 M hydrochloric acid (37% hydrochloric acid is diluted 1:5 with water) to reach pH5.5-6 with constant stirring.​

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View attachment 13960 ​

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12. The acidic extract was washed with 300 ml DCM and the water evaporated under vacuum (e.g. in a rotovap) until a viscous liquid is formed.​

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View attachment 13958 ​

13. After that, the mixture is poured into a buchner funnel and carefully filtered. At first only with gravity, then vacuum is applied until an off white solid is obtained.​

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View attachment 13950

14. The crude mephedrone hydrochloride is rinsed thoroughly with cold THF (acetone if THF is not available)​

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View attachment 13951

15. The washed product is put into a Pyrex dish, or similar and dried to constant weight. View attachment 13953 ​

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Yield 310,57g or 79,59% of theory.

K-CyanideI want almost 1 kg of finished product. can I make it 3x the amount of reagents?

 

[61-50-7]

I want almost 1 kg of finished product. can I make it 3x the amount of reagents?

tucoXxXbetter to take x4 : 2Kg of bromoketone, some people don't even reach the 50% yield + if you want it in crystal form, your yield decrease

 

[HerrHaber]

I recently achieved a greater than heard of yield of 4MMC hydrochloride in a moment when I expected it the least. Before I make it public to everyone I feel more than just 5 runs are necessary (out of 5, 2 consecutive were high yielding then 2 I thought I would improve but didn't, and another make's the triplicate required for me to state this). However I did run out of stuff and I'm looking forward to completely document this with pictures and all that. And not to be judged for holding back the "precious" information, I can trade off some counterintuitive details of the preparation:

-stirring is key (to keep DCM and water layers in the most intimate contact without phase transfer catalyst)
-relatively long reaction time (about 6 to 8h, I use taking a break by just pause the stirring assuming that if the layers are separate the reaction is almost halted)
-no heat applied (my third and fourth run had average and below yields when gentle heating was applied)
-cooling the mixture and reagents (at the acidification step chilled liquids were the best yielding)
-filter quick (just after the solids precipitate, do not let stay as part of the product will go in solution)

Hope this will help and I promise to be back with details and why not, a validation from another active member.

 

[$!$]

yes u made on micro scale 100g
somebody who made on big scale no have time wait 8h.
+ for u u try do it.

 

[HerrHaber]

yes u made on micro scale 100g
somebody who made on big scale no have time wait 8h.
+ for u u try do it.

$!$generally, when working on the development of a method small quantities and multiple runs are involved

 

[$!$]

generally, when working on the development of a method small quantities and multiple runs are involved

HerrHaberyes is true buy synthesis must be fast.
equipment dont be expensive on big scale and lab can be mobile like in RV like break bad movie.