The Vespiary

The Hive => Chemistry Discourse => Topic started by: Bwiti on April 22, 2003, 01:40:00 AM

Title: Separating Xylene From Butyrolactone..
Post by: Bwiti on April 22, 2003, 01:40:00 AM

I've read that xylene(dimethylbenzene), as a mixture of its three isomers, boils at 137*C - 140*C at normal pressure. - The Penguin Dictionary Of Science
  Since butyrolactone boils at 204 - 205*C, won't it be easy to separate the two solvents? :P

Title: Yes, also you could convert it to NaGHB and...
Post by: placebo on April 22, 2003, 03:03:00 AM

Yes, also you could convert it to NaGHB and then seperate the xylene off the top.

Title: Thanks !
Post by: Bwiti on April 22, 2003, 11:16:00 PM

Thanks for the advise! I wouldn't know how much butyrolactone was in the xylene, so the amount of needed hydroxide isn't known. The bromate/bisulfate/THF synth says 80% yield of butyrolactone, but I'd prefer to distill off the xylene first. In my dreams, xylene would be used because DCM isn't cheap to ship(haz-mat), and it smells like chloroform.[insert vomiting smiley here.] I get plenty of sodium in my diet, so KOH sounds better. Peace! 8)

Title: GBL/xylene
Post by: Chromic on April 23, 2003, 04:27:00 PM

Water holds onto the GBL far better than xylene does, and better than DCM does... although I believe it's miscible in all three. Moral: don't use xylene to extract GBL from water--use ethyl acetate, DCM, etc.

I assume there's no surfactants in the mixture, if there is... give up hope. This is what I'd do with your mixture:

While stirring, titrate with 10% NaOH to a pH of 12. Dicard the organic layer. Then from there, acidify the aqueous with ~15% sulfuric acid until the pH is around 1 (go slow) and extract that with DCM (equal volume to the aqueous, but split it into 5 extractions... ie if it's 500ml aqueous, extract 5x100ml DCM), simple distill off the DCM with no vacuum and fractionally distill GBL under vacuum.

Good luck and let us know how it goes. If you have any luck with THF->GBL I'd love to hear it.

Title: NaGHB vs KGHB
Post by: fierceness on April 23, 2003, 07:05:00 PM

Bwiti, even though you get plenty of sodium, getting too much potassium can be a very bad thing.. www.ghbinfo.com says why..

just a heads up :)

Title: money down the drain..
Post by: Bwiti on April 25, 2003, 07:19:00 AM

Good luck and let us know how it goes.

  Well, all I can say is Don't scale it up to a mole sized batch! Unless you don't mind a HUGE cloud of bromine gas. Extreme over-heating, causing cracking of glass vessel, and the risk of choking to death isn't my idea of a good time. If anyone else wants to try to pioneer this method, then use a lot more H2O, and for fuck's sake, add the bromate/bisulfate slowly! This was the most dangerous accident I've had, and I don't plan on fucking with bromine any time soon. That was some scarry shit! I'd rather tinker with essential oils, ketones, etc.. Peace 8)

Title: Btw, overheating occurred a few hours after...
Post by: Bwiti on April 25, 2003, 07:24:00 AM

Btw, overheating occurred a few hours after everything was mixed-up. Be careful, it's a delayed melt-down.

Title: Temperature control
Post by: Chromic on April 25, 2003, 01:18:00 PM

All I've got to say is use a good system of temperature control. It must not be cooled excessively, or the reaction will not happen. If it's allowed to run on it's own, you'll have the mixture spattered on your ceiling and perhaps worse.