Purification of GBL - > Help

[AquiAprender]

SWIM once talked about a bottle he had which contained both GBL(C4H602) and ethoxydiglycol (C6H14O3).

SWIM wanted to purify the GBL, getting rid of any ethoxydiglcol present.  Strangely enough, SWIM was able to obtain an MSDS for this item, which stated the product is actually 100% GBL.  But the bottle listed both ingredients.  MSDS is old, and could be out of date, or item simply contains only trace amounts of ethoxydiglycol.  SWIM isn't sure.

The boiling point of GBL and ethoxydiglycol are so close - is it even possible to use distillation to purify the GBL?  Is there another way?

Suppose also that SWIM talked once about using the GBL + NaOH to create GHB.  If there were trace amounts of ehoxydiglycol in this product, and it was used unpurified, what would happen?  Would the end results be GHB plus unreacted ethoxydiglycol?  Or would the ethoxydiglycol react with the NaOH?

SWIM is very new at this, and begs indulgence from those who know more about this...

[Rhodium]

They cannot be separated by distillation, as the boiling point is so low. I'd suggest that you add 10% aqueous NaOH slowly until all the GBL present has been converted to NaGHB (solution pH 7-8), then you dilute this solution to twice its volume with water and wash out any remaining Ethoxydiglycol (it should be relativey inert to NaOH) by shaking repeatedly with a low-boiling non-polar solvent (diethyl ether or possibly dichloromethane), then finally you boil off 3/4 of the water to concentrate the GHB solution (and any remaining non-polar solvent will be carried away with it).

You probably do not need to worry about Ethoxydiglycol traces afterwards, as at least its toxicity seems to be fairly low:

Diethylene Glycol Monoethyl Ether (Ethoxydiglycol ) Chemical Profile

(http://www.intox.org/databank/documents/chemical/diglmee/cie65.htm)

[AquiAprender]

Thank you, Rhodium.  SWIM will be very grateful for your help.

[Chromic]

Titrate with NaOH to convert the GBL to NaGHB, then under a water aspirator vacuum, distill off everything to dryness.

Now, it might be at a suitable purity to ingest... but if you want to make sure, reconvert to GBL using concentrated sulfuric acid, extract with DCM, distill off DCM then vacuum distill the GBL. (it may even be possible to distill GBL from the sulfuric acid.. might be a convenient time-saving step)

[Rhodium]

That sounds like an even better idea.