Author Topic: Recrystallisation problem  (Read 7128 times)

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  • Guest
Recrystallisation problem
« on: March 19, 2004, 12:55:00 PM »
The result of SWIMS latest NaBH4 synth was a mixture of MDMA and MDEA free base. SWIM used a mixture of little methylamine and a larger amount of ethylamine in cold MeOH to produce the imine. After gasing the freebase solution (in toluene) with HCL small yellow to light brown crystals were formed. So SWIM decided to do a recrystallisation. SWIM took 23.6 grams of crystals and dissolved them in boiling IPA. The IPA turned very light brown. However, little pieces of off-white material didn´t dissolve. SWIM filtered the hot solultion and allowed the IPA solution to cool very slowly. White crystals started to form and after 1 day at -18 C almost 15 grams of crystals were collected. The grey material was scraped of the filter and another 4 grams of material was recovered. So far so good...When a GC/MS analysis was performed the results were quite surprising. The white crystals consist of MDEA only whereas the material scraped off the filter consisted of a MDMA and MDEA mixture (1 part MDEA to 8 parts MDMA). Is the solubility of MDMA so much different from MDEA? Or is there another explanation for this behaviour??


  • Guest
MDEA recrystalization
« Reply #1 on: September 26, 2004, 03:34:00 PM »
Does one know how to recrystalize MDEA ? I've read that it is soluable in IPA (like MDMA is), but in my case it is not. A writeup on Rhodium's site says to add some H2O. I added a few ml and everything dissolved, but is this really a good way to do it? I thought there will be a loss because of the water, is this true? Can acetone be used instead of IPA ?


  • Guest
multiple solvent crystallizations
« Reply #2 on: September 26, 2004, 03:42:00 PM »
Multiple solvent recrystallizations are based on adjusting the solubility in the primary solvent by adding small amounts of other solvents.

In your case, you can add either water to increase solubility of your salt, or acetone to decrease solubility. Maybe you should dissolve in hot IPA/water, cool, collect crystals and reduce volume of mother liqor to 1/2 of original. Now add dry acetone until solution becomes turbid. Cool & filter again. Repeat if you think substantial amounts are still missing...

Have you already tried diethyl ether with EtOH for reXtalization BTW?



  • Guest
« Reply #3 on: September 27, 2004, 09:02:00 AM »


  • Guest
MDMA recrystallizes well in IPA, SWIM gets a...
« Reply #4 on: September 28, 2004, 08:12:00 PM »
MDMA recrystallizes well in IPA, SWIM gets a nice crystalline product via the IPA method, just add enough IPA to cover the crystals, then heat to boiling then add more IPA until all the  product is dissolved.  Cool to RT, then put in your fridge,
and finally the freezer. :)

I'm sure MDEA wouldn't be much different.
BTW run your reactions seperately, there wouldn't be a need to filter your product in such a manner.


  • Guest
It is different...
« Reply #5 on: September 30, 2004, 07:36:00 AM »
Hi amine. MDMA recrytallization is quiet easy, i do it like you in IPA - no problem. Try it with MDEA, you will see the difference. I've read that it should be soluable in IPA, but it is not. You will get a snowwhite IPA solution, but the cryystalls do not dissolve properly. After adding a few drops of water, the solution turns waterwhite and everything dissolves. Even the crystals look totally different. MDMA xtals are big grained and rockhard, MDEA xtals look like MDA, a snowwhite powder, much smaller xtals.
Finally i like the product, it's different to MDMA but i can recommend the turn - much better than MDA (my personal experience).