4-mmc and pitfalls during oxidation and production

[zetvasa9]

Hello, dear comrades, I have a question about (Mefa) 4-mmc. How to return 4-mmc to flour after trying to acidify it with aqueous hydrochloric acid. The method is to send it straight to crystallization, but alas, the input from 4 kg of Bk-4 is only 800g. Despite the fact that when I worked through flour, the output was 70%. . Here I have about 60 liters of mefa in solvent and water, tell me how I can convert it from this base into flour. Sorry for the broken language. Maybe we will soon be EU. I will be very grateful if someone helps. I am ready to thank someone who knows 4-mmc very well and will help to establish production, since from 50 liters of MPF we got no more than 10 kg.

 

[dnBQByvHb8Zkawbjpx]

During acidification with HCl (aq) the 4MMC.HCl salt precipitates and the solution turns into a slurry. Filter it and you get a paste, rinse it with acetone to remove residual solvent and acid, put the paste into a tray spread in a thin layer, let the acetone evaporate and voila: you have 4MMC.HCl powder. However, the powder should be recrystallized to purify the final product.

 

[Precursor-hk]

1. Acidification and Salt Formation:
- Ensure Complete Acidification: If you haven't already, make sure the base form of 4-MMC is fully acidified by adding hydrochloric acid until the pH is around 5.5-6. This step forms the hydrochloride salt of 4-MMC, which is more likely to crystallize.

- Solvent Selection: You mentioned having 60 liters of Mefa in solvent and water. If the solvent is dichloromethane (DCM) as indicated in some synthesis procedures, you would want to separate the aqueous layer after acidification since the hydrochloride salt will be in the aqueous phase. If you're using another solvent, ensure it's compatible with water for phase separation.

### 2. Crystallization:
- Cooling: Cool the mixture down significantly, ideally in a freezer, to promote crystallization. This step is crucial as it helps in forming solid crystals from the dissolved salt.

- Filtration: After cooling, filter the solution to separate the crystals from the liquid. Use filter paper or a Büchner funnel for this purpose to ensure you capture as much of the solid as possible.

### 3. Washing:
- Rinse Crystals: Wash the crystals with a small amount of cold solvent (like isopropanol or acetone) to remove impurities. This step should be done carefully to avoid dissolving the salt back into the solvent.

4. Drying:
- Air Dry or Oven: After washing, let the crystals air dry on the filter or use a vacuum oven at a low temperature to dry them completely. This will turn your product into a dry, powdery form similar to flour.
5. Grinding (if necessary):
- If the crystals are too large, you might want to grind them down to achieve a more flour-like consistency. Use a mortar and pestle or a clean coffee grinder for this, ensuring no cross-contamination with other substances.

 

[zetvasa9]

How do these guys get such blocks of crystals?
I have come across this question many times but no one gives the answer what is the secret

 

[Precursor-hk]

Please tell me what method you use and I will help you.

 

[zetvasa9]

We use regular evaporation in glass trays after acidification. We tried many methods, but none of them gave normal results.

 

[HardWork]

You just need to make powder first and later recrystallise it.