Author Topic: Sandmeyer GBL Synth  (Read 1871 times)

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Gravimetric

  • Guest
Sandmeyer GBL Synth
« on: October 13, 2004, 05:59:00 AM »
I've been reading through the Sandmeyer GBL synth here :

https://www.thevespiary.org/rhodium/Rhodium/chemistry/gaba2gbl.html


and am slightly confused when it gets to the extraction part. It talks about using DCM as an extractor, but isn't GBL water soluble? Or is it just "more soluble" in DCM (or chloroform?) so it moves into the DCM/Chloroform layer. If someone were to do this without doing "Step 1" (the simple distillation) which solvent would the GBL end up in?

Sorry if this sounds like a stupid question (and it probably is), it just seems confusing to as to why an organic solvent is used when GBL is water soluble, and so are the other end products.

Thanks :)

OcoteaCymbarum

  • Guest
This should help
« Reply #1 on: October 13, 2004, 06:29:00 AM »
See that post, i think it will help you

Post 454516 (missing)

(Rhodium: "A/B of GHB/GBL", Chemistry Discourse)

fierceness

  • Guest
Yes, GBL is miscible with water.
« Reply #2 on: October 13, 2004, 02:18:00 PM »
Yes, GBL is miscible with water.  However, it is also miscible with DCM.  DCM is not miscible with water.  So you get 2 layers, a water/gbl/crap layer and a DCM/GBL layer.  If you extract with DCM several times you can extract almost all of the GBL out of the water, so you are left with only DCM/GBL.  Then you distill.

Gravimetric

  • Guest
Thanks, I had a vague feeling it was something
« Reply #3 on: October 14, 2004, 12:09:00 AM »
Thanks, I had a vague feeling it was something like that. If you were unable to do the Step 1 part of the extraction, could you increase the yeild of the DCM/Chloroform extraction a worthwhile amount by adding a quantity of highly contentrated salt water/brine, as per Rhodium's post in that link. Would this be worth it on a small scale (estimate yeild of 50~100ml GBL) or would the extra hassle (not that there's much) be too much for the increase in GBL extrated.