Question resolution again

johski

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hey, who can explain to me exactly how to separate the d-meth isomer from racemate meth? I'm not really smart from the instructions described.. can someone who has done it themselves explain to me how they did it?
can i simply let the meth racemate react with the d-tartaric acid and methanol under heat and separate them in a separating funnel? One of the two phases then contains the d-isomer, which I let crystallize out as the methanol evaporates? if so, which phase does the d-isomer contain? Unfortunately, I only have limited chemicals available.
I would be extremely grateful if someone would take the time to help me as a chemistry beginner.. maybe someone will message me? does it only work with the freebase or also with the hcl?
i have ordered d-tartaric acid from china, how can i find out if it really is d-tartaric acid? I'm actually sure that the cas number is the right one.
I would be really grateful to you.
regards
 

MadHatter

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You have racemic methamphetamine freebase. You pour in L-(+)-tartaric acid. There will be a salt forming. This salt is L-methamphetamine tartrate. Vacuum filter the solution. The L-methamphetamine tartrate will stay in the filter paper. In the bottle below you'll have D-methamphetamine freebase. You gas this with HCl gas and get D-meth HCl.

In theory. In practice, you might need to do the salting with L-(+)-tartaric acid several times to get most of the L-meth out. The resulting product will not be entirely pure D-meth either, but mostly D-meth.

Also, you need to understand the nomenclature of tartaric acid. D-tartaric acid is not the same as d-tartaric acid (with lowercase d). It's pretty confusing and complicated. This is the key:
L-(+)-Tartaric acid (modern name) = L-tartaric acid = d-tartaric acid (old name) = cheap, natural, accessible
D-(-)-Tartaric acid (modern name)= D-tartaric acid = l-tartaric acid (old name)= expensive, synthetic, hard to get


You should use and look at the prefixes L-(+)-tartaric acid and D-(-)-tartaric acid.
L-(+)-tartaric acid will salt out L-methamphetamine and D-(-)-tartaric acid will salt out D-meth as a tartrate salt.
 

johski

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l tartaric acid was called earlier d tartaric acid?

how i can gas with hcl?
Or is it just enough to mix and stir?
 

MadHatter

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No! You need to see the difference between lowercase letter s "d"/"D" and "l"/"L". These mean different things.
L-(+)-tartaric acid (uppercase "L") is the same as d-tartaric acid (lowercase "d").
D-(-)-tartaric acid (uppercase "D") is the same as l-tartaric acid (lowercase "l").

The lowercase names are old and not really used anymore. Except in some synth descriptions, which makes the whole thing really confusing. The background is complicated and has to do with different systems of naming molecules in the past and now depending on how they're drawn or how they rotate polarized light.

There is an excellent description of how to generate and use dry HCl gas on this site. Use the search function.
 
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