Hi can anyone help me with the recrystallization of methamphetamines, after separating the isomers as well as acetone washing. Every time I have the problem that no real crystals form. It was recrystallized with dcm/acetone also with h20 (7 days) . But I always get flat papers. Can anyone tell me what the problem is? The quality is good - after reagent test, it is also the right product. Thank you for your help
The crystals shape is determined by the solvent. Perhaps try a few different mixtures? Are you evaporating it down until you start to see snowflakes? With iso/acetone I get iridescent flakes and with iso/h2o I get spiky blobs Like a sea urchin. I'd love to see some weird crystals and what the solvent was
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- By Acab1312
Which solvent would you recommend to get crystals such as btcboss2022? I dissolve the product in a solvent and let it evaporate until a skin forms on the surface, then it is slowly cooled 24 room temperature, then 48 hours, refrigerator, if not with h2o, then another 72 hours then I continuously get this result. At first I thought it was due to the isomeric separation that the ee value is too low, but now I have separated it 2 times in a row with the similar end result
Uh, that is exactly L-meth to my eye, racemic at best
- By Acab1312
Thank you very much my friend you were right that was the L isomer. Have all my precipitate of isomeric separation, acidified, acetone crash and recrystallized now looks like the desired product. I can confirm that L(+) tartaric acid has the desired isomer in the precipitate not in the h20 solution. What fascinates me is that people found the L-meth very good and active. Thank you sincerely 
It just so happens that I spent hours hunting down literature that showed the difference. At the microscopic level, D- meth is "rays ", long and slim,and L- meth is square shaped and has the appearance of a 4-leaf clover. Racemic meth can't produce the stellagtite shaped shards and when you look closely you can see the 2 different crystal structures
You need the d meth not the l meth you can throw the l meth away it is useless
You can resolve it into D-methamphetamine via a couple of pathways an sn2 reaction (an inversion, a backside attack) is one way
danke nochmal
Yes, the attributions for the isomeric separation with L-tartaric acid were wrong. There it was said that d-meth is in the mother solution, but unfortunately that was wrong the desired isomer was in the precipitate. Luckily I kept all my precipitate and was able to extract it now.
- By Zan444
So i was right and the l-meth was white and the d-meth transparent right?
