Separation of GBL from crap.

[Novice]

I have a mixture of GBL, D-lemonene and "C9/C11 fattyalcoholethoxylate" (CAS 68439-46-3) and would like to isolate the GBL.

The MSDS say that the product contains:

D-lemonene <10%
Gamma butyrolactone >30%
C9/C11 Fattyalcoholethoxylate <10%

Now can I assume the mixture contains at least 80% GBL? Or is there a possibility that there is water in there as well, but it's excluded from the MSDS?

D-lemonene is a cyclic alkene and is easy to wash away with DCM, but what about fattyalcoholethoxylate? This specific variation has 4 moles of ethylene oxide groups, and MERCK states that "compounds with one to five moles ethylene oxide are sol in oil and many hydrocarbons. Water soly increase with increasing ethylene oxide content."

Does this mean that my compound is soluble in other non-polar solvents as well, such as DCM?

Will basification with NaOH damage the fattyalcoholethoxylate?

Thanks!

[hest]

You have 30% GHB and 70% crap, that a bad startingpoint.
remember that you will ingest 2-3g material, so it has to bee pure!.
The ester of fatyyacid will cleave with NaOH and they are all sol. in DCM I guess. Destilate the GHB out of the mixture is a start.

[fierceness]

Correct me if i'm wrong, but GBL is soluble in DCM.  In fact, swif has used it to extract GBL before.  So, using it to remove the D-limonene will also get the GBL.

[Novice]

Well, that's what I was wondering actually... The MSDS says >30% GBL, which means *no less* than 30%. <20% of the other substances means at most 20% crap. The rest must be GBL with or without water.

A gut feeling says that if 50% of the mixture was water, then it would be an ineffective solvent for taking care of grafiti and such, which the tradename of the product indicates that it's for.

I'm aware that GBL is soluble in DCM - let me clarify my original question.

Do you people think the method I describe below would be a functional method for isolating GBL from the above mentioned solution?

Treat (reflux) the mixture with enough ~10% MOH¹ solution to make the pH=7-8, do a couple of DCM washes to get rid of the D-lemonene and fattyalcoholethoxylate², distill off the volatiles to get a mixture of M-GHB and MOH. Acidify with e.g. 10% H₂SO₄ till pH=<2-3 and then extract the formed GBL with DCM, evaporate and distill the GBL at atmospheric pressure.

¹M = alkali
²IIRC GBL is easily hydrolyzed by OH^-, easier than many other esters. Is it correct to assum that the GBL will be completely hydrolyzed before any of the fattyalcoholethoxylate gets hydrolyzed as well?

Thanks!

[Rhodium]

The ethoxylate is a detergent, which makes it soluble in both aqueous and non-polar solvents, and this feature may make it hard to remove by a simple wash. The residues might perhaps be removed by treating a dilute aqueous solution of the once-distilled butyrolactone with activated carbon.

[Novice]

Thank you very much Rhodium!

I'll try and improvice my way to a result, with your information in mind.