NMP/GBL hydrolysis. Impulse goofing.

Rather than screw up the thread that spawned this: http://www.sciencemadness.org/talk/viewthread.php?tid=7538

Winding away the idle hours:

400ml of 80/20 % NMP/GBL was added promptly to a still hot, equal volume of 25% NaOH in the reflux vessel. This is placed in an warm oil bath which was brought up to average ~130°C for 2 hours; gently boiling the supernatant. Although the bath did peak around 150°C with the last adjustment.

The vent hose was run into a water/naptha trap during this time. No activity was anticipated at the trap, however the water readily catches something, turning milky white. No noticeable change in the naptha layer appearance or volume. Unfortunately these layers were not measured/weighed before & after. Trap layers were seperated & dried post rxn. The water left behind a tenaciously clinging white residue. No odor of any significance this whole time with it while evaporating. The organic layer was evap'd at room temp and a strong ketone-ish, nail polish remover-kindasorta sweetish odor permeates the immediate area after some hours. Without ever having been up close & personal with GBL, I don't know if this odor is characteristic of it. Oh well. It lingers here still, for no discernable reason. I'm wonding if an old can of solvents hasn't finally rusted through somewhere in that dump of a cupboard. Maybe the wife spilled something somewhere. Crap.

The milky white, stubborn residue from the water was disposed of in short order due to company coming over & wife pissed about the damn pie plate. Perhaps this was denatonium benzoate as the denaturant? Some trace amount is told to be in there...

I suppose solubility tests should have been checked on this. Oh well.

The reflux proceeds at a rolling boil during this time and note was made of a salty looking, heavy sediment forming on the vessel bottom. Supernatant becomes clear, medium bown. Like Widmer Heffeweizen. After this time period, reflux is stopped and allowed to reach room temp.

The majority of the liquid maybe ~90% forms a top layer. Beneath this is a white, salty substance, itself atop another dense liquid layer of the same clear, dark brown appearance, comprising perhaps another ~5% . At the bottom of all sits the first noted, salty sediment. Nothing extracted otherwise at this point. Just placed in the freezer & allowed to seperate further. Some 4 hours of this shows a salt sediment as before, on the bottom. Above this, to equal nearly 50% total volume, lies a blanket of delicate looking, clear crystalline mass. Perhaps Na 4-methyl amino butyrate, primarily per this volume with possible NaGHB forming the minor sediment & saturating the solution? One supposes that cold filtration & washing/solubility testing will follow after some sleep is achieved.

At any rate, that's where it stays for now; potential denatonium benzoate (ie Bitrex) be damned. The thought of this stuff being in there is annoying.

From here: http://www.bitrex.com/pages/technical_frameset.htm
"Depending on conditions Bitrex is generally considered to be heat stable at temperatures of up to 140°C."
What the hell manner of side product(s) might this ugly critter produce? Lidocaine? Perhaps several lighter things that may have distilled over to some degree in any case; broken off of the denatonium at the Nitrogens? What of that benzoate?

Anyway, regarding the 4-methyl amino butyrate: It looks to me that phenibut & baclofen are possible directions. ?

[Edited on 5-2-2007 by Misanthropy]

Crude, I know, but I'm no chemist. I’m just trying to learn by observation.

I was meaning to hydrolyze both by way of excess base & heat, so long as the resultant NaGHB is not further altered in any way by this. Have I not gone far enough? I'd like to see this NMP completely converted to 4-methylamino butyrate spoken of in Org's thread, listed above.

I was thinking of cold filtering the crystalline solids & refluxing again, this mother liquor, to see if any further conversion occurs. Might I use even more heat?

This is my primary interest; I was merely noting the goings on at the water trap to get some feedback on it separately.

This milky white, polar distillate that dries to a small amount of white powder, makes me think in the direction of Denatonium Benzoate. It is added in small amounts, to the original product as a bittering/denaturing compound. That's only of interest insofar as getting it out of the (hopefully) 4-MAB/GHB solution.

Both of those compounds are academically interesting in their own rights, to me. I have no practical use for either of them, nor any number of things I wind up with. I'm doing for the sake of doing and maybe understanding the nature of these things further as I have no formal education in this field.

Apologies for any confusion or miscommunication on my part, and thank you for your time & consideration, everyone/anyone!

Nicodem: Again, I apologize for my lack of education in this field; I'm just learning on my own (trying, anyway). I appreciate your feedback as the breadth & depth of your insight in these things is considerable and I SWEAR I'm not trying to be rude by offering up such basic questions....

I'm not intentionally being a prick; I'm just a natural annoyance it seems.

I didn't readily find (on Google), specific documentation detailing that question. Being financially disadvantaged; I don't have an extensive reference library & am most frequently searching the net over very poor dial up..... Might you help me locate the applicable literature?

Because I'm a novice, posting in the appropriate forum. Also, I'm deviating to some fair degree, from what Org was meaning to learn from his thread in Gen Chem.

Out of respect, I'll introduce whatever ignorance I may, into my own thread, not his.

I assume this is what you were asking?

At any rate, I took a peek at the Jug 'O' stuff & noticed 2 distinct crystalline layers, white/salty on bottom & clear/dense shards above. Atop this crystalline cake lies a fatty, soft, off white layer. Half heartedly adhering to the solid upper crystalline layer's rough surface. Giving & releasing with agitation.

I assume this was an unlisted thickening/emollient agent for the GBL before it was mixed with NMP; thereby forming the final product I'm tinkering with now. Perhaps hydroxypropylcellulose or similar? The original mix was a light brown gel. Neither NMP nor GBL are said to exhibit either this colour nor viscosity.

I don't know for sure about what it may have been, but that's my best guess. It now looks like a layer of fat from a corned beef. Or the pantry rat soap I made as a kid.

One compound I DON'T want appears to have eliminated itself from the mixture anyway & that's not so bad. I found the following regarding thickening agents used with GBL. From here: http://www.patentstorm.us/patents/6156711-fulltext.html
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The medium brown liquid above all, about 50% total volume, is of a much thinner consistancy now. I guess I'll decant, filter & reflux with yet more Lye. Perhaps something new & exciting will happen. Like eating the bottom out of the jug.

[Edited on 2-10-2007 by Misanthropy]

Thank you Nicodem, for the first post which is at least on topic.

So then, the addition of the electronegative -O in the -OH, or a resultant loss/replacement of hydrogen, is effectively an oxidation via hydroxylation? Ok.

Now, in the case of this NMP hydrolysis, where it is opening the bond between the N and the C=O, the N gains a hydrogen whereas the now exposed bonding point of the C=O carbon takes on an O-, rather than a hydroxyl (-OH) group per se (That's forming a carboxylic acid then, yeah?). The O & H dissociating & bonding to seperate locations of the target molecule?



Then when acidified, maybe with H2SO4, this (dehydrates?) rips that O off that carbon (and a hydrogen from the N) causing esterification back to the lactam perhaps? The same being true for GHB -> GBL? G-MAB -> NMP just being more difficult due to the amine being a bit more resistant to this attack than is GHB?

Or do I still have this wrong?