Sandmeyer GBL proceedure, few quick questions...

[JFish15]

Originally Posted by AdMech

This is basically soh's original post, except cleaned up and re-written as I understood it... so if anyone could read over it, I'd appreciate it. The stuff in {}s is mostly what I added, and the bolded parts are the only two parts I feel I don't understand completely.

When you've boiled off enough water, the rest of the distillant becomes saturated with salt. Since only about 36 g of salt can dissolve per 100 mL of pure H2O and considering there are other dissolved solutes it starts precipitating out and causing the bump which sounds like little mini explosions and they essentially shake your apparatus. At this point you want to take your flask off the heat source, let it cool, then decant or filter your distillant. Add more post reaction fluid or water. Easy.

8.5-9. Since I only used pH strips 9 was always enough to tell for me that everything was converted, but I couldn't discern the variations in color that much. Anyway, they say what's safe for human consumptions like 2.5-9.3 or something like that. But yeah, don't do like me in my very first reactions and go to like 12-13. To where the shit burnt your tounge and you had to mix it in a cola or acidic beverage to neutralize it and it also made it taste flat and salty.

[not a troll account]

Originally Posted by AdMech

This is basically soh's original post, except cleaned up and re-written as I understood it... so if anyone could read over it, I'd appreciate it. The stuff in {}s is mostly what I added, and the bolded parts are the only two parts I feel I don't understand completely.

You could calculate how much CaCl2 or NaCl you need to depress the freezing point, but don't bother because the ice you add is just going to dilute it. Personally I just saturate the solution, it's not like salt is expensive. Also don't try to go by a number for changing the ice bath, change it as needed to maintain the desired temperature.

We bring the pH back up before distilling because adding a base is going to form salt. We don't want to bring it too high though or our GBL will turn to GHB before it stills over. People claim varying results depending on what pH they distill it at, but that aside, we're going to form some salt regardless so we would rather form the salt in our solution than the distillate.

It's not imperative that you follow exact ratios for the distillation. If you're looking for somewhere to start then by all means we have some well tested ratios in this thread, but feel free to distill it in a way that works well for your reaction. Just keep distilling up to the point where it would be easier/faster to add more water and go again than keep distilling the current pot.

Whereas before we were adding base to neutralize any excess acid, now that our GBL/water is distilled over, we're adding base to convert it to NaGHB. Add slowly and keep stirring, checking pH frequently. The reaction is equimolar with no byproducts. Once pH rises to 7-8, it's all converted and you're just adding lye to your product. However, HPC recommends you boil down at pH 9 minimum or free GHB will boil away with the water. You bring back down the pH with NaHCO3 in the end, but this adds unnecessary salt to the final product. So it seems to be a trade off be better yields or less salt.

Also, you might want to distill around pH 4-5 rather than the originally stated pH 6 as GBL somewhat acidic itself, pKa 4.5.

[grant71]

Is there any easy way to clean up the solid ghb? As in to remove any unreacted chemicals. Been reading on ways to recrystallize it and yield a more pure product.

[JFish15]

Originally Posted by grant71

Is there any easy way to clean up the solid ghb? As in to remove any unreacted chemicals. Been reading on ways to recrystallize it and yield a more pure product.

Uhh yeah, grain alcohol man. 95% ethanol does the trick great. In as little as you can dissolve it in. Then filtering and boiling down again like you just did previously. Haven't you done this before?

[grant71]

Originally Posted by JFish15

Uhh yeah, grain alcohol man. 95% ethanol does the trick great. In as little as you can dissolve it in. Then filtering and boiling down again like you just did previously. Haven't you done this before?

Haven't done it before. So maybe some everclear would do the trick. I will have to try that. Will it leave any nasty tastes etc from the alcohol?

Not quite the chemist most of ya are. So any leftover nano2, naoh, etc would not dissolve in the grain alcohol?

What would boiling the final product in activated charcoal remove?

[JFish15]

Originally Posted by grant71

Haven't done it before. So maybe some everclear would do the trick. I will have to try that. Will it leave any nasty tastes etc from the alcohol?

Not quite the chemist most of ya are. So any leftover nano2, naoh, etc would not dissolve in the grain alcohol?

What would boiling the final product in activated charcoal remove?

Nope, absolutely not. The alcohol will boil out, when its dry its dry and will be almost totally pure and tasteless. But no, no nitrite or hydroxides or salt should be in your final product. The big mass of shit that you filter out should make you feel better.

As for the charcoal, I'm not really sure, but I know it's a good thing to do

[grant71]

Swim tried this. Used grain alcohol. It was a pain but most if not all of the product dissolved in it. Keeping it hot, etc, and trying to filter it didn't work well. It thickened up very quickly and wouldn't filter. Did one not use enough alcohol to thin it out? Does one need to filter it when it is hot or cold? Does the unwanted products become insolluable when the alcohol is cold or does it matter?

[Ckfcfs]

Hi guys

swim would like to know whether a home Water distillation unit would do the job for extraction?

Also would distilling remove any impurities from using LR grade nitrite and hcl. If the hydroxide is AR grade, would this suffice?

Swim main concern is purity. How would one remove nitrosamines from water?*Throwing out the first 10ml of distillate doesn't reassure lol. Activated charcoal?

thanks

[not a troll account]

It depends how the home water distillation unit is built, but probably not. People in this thread have used copper condensers before and it'll shit all over your product and probably ruin the water distillation unit as well.

I can't comment specifically on the impurities, but if you make NaGHB you're also crystallizing out of solution, purifying it further. Now the question is would the nitrosamine salts stay in solution or crystallize out and contaminate the NaGHB as well?

[grant71]

Swim got the recrystalization to work. Filtered the hot ethanol solution but didn't get hardly anything in the filter, as one would expect to. It definitely didn't seem worth the effort.

[grant71]

So...when swim is doing the activated charcoal workup on the distillate...and after filtering and adding naoh, the reaction produces a dark precipate that has to be filtered out.....it only appears after adding the naoh. Swim has to let this settle and filter it out as well. What is it??

[e0s]

How come Chromic's writeup (on Rhodium) can get 475g NaGHB from 309g GABA, is it because of all the solvent extraction?

Does stateofhack's GBL-water azeotrope distillation method leave a lot of GBL behind which can be DCM extracted (hopefully using significantly less solvent than in Chromic's writeup)

Also is GBL volatile? If you were to leave a DCM solution of GBL to evaporate atmospherically would GBL losses be minimal? (I distill and recycle my solvents of course),

[warmonger]

Buddy of mine was wondering about the so called sandmayer reaction of gaba to ghb synthesis. What would the result be if after letting the reaction sit for 24 hours instead of distilling one would boil it in activated charcoal right away and then raising the ph to 7.5 to transform it onto ghb. how nasty/dirty would that ghb be?

[warmonger]

In this forum there is a post about this reaction and the poster mentioned that it took him an hour and a half to drip around 1000ml of hcl 35% into the reaction without it over heating or causing brown gasses. monkey has tried this reaction and it took himn over an hour to drip 100ml hcl to be able to control the temp of the reaction. is there something monkey is doing wrong? (rxn was cooled to -7 and placed in an ice bath)

[warmonger]

how come you can add so much hcl to the rxn in an hour and a half without it overheating?

[PSYenceFRYday]

Would the reaction go at dry ice temperatures? That would seem to be a great way to ensure no NO2 is formed, and could also feasibly be used in case of emergency (HCl is added to fast) to rapidly relieve heat from the system.

Also, how well would a basic ammonia scrubber solution work for neutralizing the NO2 fumes if evolved?

[beefcake1]

Hi guys.

Swim's cat did a 1 mol rxn, and the best he could get was 42g of a slightly green waxy solid at the end - smells and tastes like NaGHB however. When the cat consumed 2g of it, only a mild threshold effect was felt, indicating it might be weak/impure.

pH of the post rxn fluid was about 3.25. Brought it up to about 4.5 before distillation - took about 75ml of 20% NaOH solution. Got a nice clear distillate, as described by other swiys.

pH of the distillate was about 2. Brought it up to 8.5 with lots of stirring. The solution acts like an indicator during this process, changes colour between pale yellow, clear and pale green depending on pH. It took a lot of slow additions to get it to stay above 8 - obviously NaOH is reacting at this stage. Took about 60ml of 20% NaOH in the end. It was a pale green colour before the boil down.

After getting it to 8.5, the pH did seem to drop down a lot during the boil down, and then rose up to around 7 just before waxing. It was taken off the heat when temp rose to about 130 deg C, and produced a thicker greenish solid.

Is this difference in colour expected? Or could it be an excess of salt? Should a pure product be totally white?

[Hydroponichronic]

Originally Posted by beefcake1

Is this difference in colour expected? Or could it be an excess of salt? Should a pure product be totally white?

Out of curiosity, what kind of condenser did your cat use? If if was metal, that would explain the green color. My buddy's cat had the same problem. He never really resolved it, for lack of a better condenser. As for the bulk impurity, I have no idea.

[beefcake1]

Originally Posted by Hydroponichronic

Out of curiosity, what kind of condenser did your cat use? If if was metal, that would explain the green color. My buddy's cat had the same problem. He never really resolved it, for lack of a better condenser. As for the bulk impurity, I have no idea.

No, all glass... And as far as I know, all 99%+ pure chemicals. No idea where the colour can be coming from. It is definitely related to pH, it seems to be yellow below about 8 and green above 8 (only a mild tint, but once it boils down, gets stronger).

[Hydroponichronic]

Originally Posted by beefcake1

No, all glass... And as far as I know, all 99%+ pure chemicals. No idea where the colour can be coming from. It is definitely related to pH, it seems to be yellow below about 8 and green above 8 (only a mild tint, but once it boils down, gets stronger).

Hm... Well, my buddy's cat did observe the same phenom, but it was using a metal condenser and thought it was the nickel ions coming off the condenser from acid distillation. That is weird, though. I don't know, then. Maybe there's some kind of side-rxn going on with the nitrite ion? TBH, I don't know.

[BungHole]

Maybe the diazonium intermediate reacted with a reaction by-product?

[PSYenceFRYday]

Working on devising an additive mixture that can be implemented to prevent rape with this substance, which I think would significantly forward safety in the research scene. I wil be posting more as I make progress, I strongly encourage anyone to contribute ideas/comments, this could be a fun collab. project for the zoklet thinktank xD .


Here's the outline of the ideal characteristics/ design strategy:
1.) Must be 100% non-toxic and have no risk of side effects(ideally FDA approved in some country)
2.) No reaction with water/ GHB dilution. Must be soluble in water/GHB under normal conditions.
3.) Specifically reacts with ethanol to form a pungent/offensive smell that distinctively initiates a smells "off" or undesirable negative feedback psychological response. Essentially parallel in application as H2S in consumer propane mixtures.
4.) Bonus cookie/alternative effect: precipitation reaction with alcohol, in which the addition of the additive to alcohol creates a distinguishably "off-looking" sludge precipitate in the drink. Basically in this effect, adding alcohol to the additive makes an unappetizing/gross/jankee looking product that one would look at, and know that something is wrong with their drink.

[beefcake1]

Forgot to follow up on this earlier... The cat was being a fucking retard - turns out it dipped a few indicator strips in the product at some point in the process. When it stopped doing that it started getting delicious pure white product.

[Hydroponichronic]

Originally Posted by beefcake1

Forgot to follow up on this earlier... The cat was being a fucking retard - turns out it dipped a few indicator strips in the product at some point in the process. When it stopped doing that it started getting delicious pure white product.

lol, happens to the best of pets.

[shroomy]

Hey guys just wanted to see if there was any substitute for the NaNO2 as I am having a very hard time trying to acquire some here in Australia ? the only place i see it available in its pure form is from e-bay and the account look like they are set up to catch terrorists or people doing dodgy stuff with it ?

I have been wanting to give this a try for some time now and finally am ready

[shroomy]

test post

[Subflow22]

Greetings,

New to the forum, 1st post. I've come here often over the years for bits an pieces that I can usually only find here. Sandmeyer was my first real reason for coming to this site, so I figured I'd give something back.

I found the doc in the link below out on the etherspace. Someone else posted it somewhere else, and it was promptly ripped down. Thanks to Google cache, it has been resurrected. Hope it helps someone, as it definitely answered a lot of little questions that I otherwise would have had to work through via painful trial and error.

I personally, collect this type of information purely for the novelty of gathering chemical synthesis. I have never and would never perform this or any other activity that could be deemed illegal. Informational purposes only.

I couldn't post attachments, so the doc will be available as long as the gmail account hosting it:

https://docs.google.com/viewer?a=v&p...MTY0ZGVi&hl=en

Best Regards

[Gun Lover]

Fukken saved

Thank you

[Troypants]

Ok so my first half assed sandmeyer is in the first hour of it's 24 hour reaction. I used 11% nitrite Prague powder so there is slot of salt in there. Was also quite inebriated when I added the HCL so a little brown gas evolved.

Used 103g GABA
55g sodium nitrite (+lots of nacl as it was Prague powder)
~200ml of 280g/L HCl

Any tips? Should I filter off all the salt before I move to distilling or just see how I go.

Thanks in advance -Troy

[click2]

Just filter off the salt, distill. I personally would skip the long distillation and extract with DCM. This way you're not sitting there messing with a random amount of GBL in solution. just evap the DCM, heat with norite. Much simpler.

[getboss]

Ok i know this thread has been dead a bit but i want to make sure i have a legit reaction setup before i begin. I will be using a 1l flat bottom flask with a 500ml separation funnel w/ a ptfe valve to control the hcl drip. In between those i will have an adapter with a gas line running to the outside. I know this is a simple reaction setup but will this work correctly? On a side note i have a full distillation setup that mimics the ones at my current university.

[getboss]

also will be using 99%technical grade sodium nitrite and everything else will be acs grade so there should not be a problem, correct?

[s1monster]

Quick question on the Sandmeyer workup discussion.
Of the two workups mentioned, one relied on Azeotropic distillation alone, while the other used a combination of first azeotropic distillation and then Solvent extraction via DCM.My question would be:
What else if anything other than GBL is carried over Via Azeotropic distillation or via Solvent extraction using DCM?

[frozenveinz]

Nvm.

[sigma462]

Just to recap, for the myriad of questions readers might be having after reading this thread.

GBL forms an equilibrium with GHB, this is a ring opening/closing reaction which is catalysable by both acid or base. As it turns out at pH < 5 GBL (the closed ring lactone is formed) as the main product, at high pH gamma-hydroxy butyr(ate) is formed.

Here's a dandy file hosted on Erowid, it shows that at pH < 5 there is always a 2:1 ratio of GBL to GHB OVER TIME (3 days or so)

http://www.erowid.org/archive/rhodiu...sic.issues.pdf

Cool. If you read the entire article you will find that isolation of the free-acid (gamma-hydroxybut(yric) acid) is not possible as even trace amounts of acid (water is slightly acidic mind you) will catalyse the interconversion. Due to this you will not find the melting/boiling points of the free acid ANYWHERE in the literature.

Now to (try) and clarify some points on the process:

To keep the reaction temperature low at all times you can supersaturate water with table salt and stick it in the freezer over a period of a day or so, if you check the temperature of the solution you will find that it is well below 0º C. If you have enough of this solution at hand you can be damn sure you'll be able to control the temperature. Salt is remarkably cheap. If your freezer is not big enough and you live in a cold country where you have winter seasons then take advantage of this.

The reaction has to be stirred VIGOROUSLY, most stirrers in the $100-200 range will easily stir PURE WATER solutions of 2 - 3 L with no problem. This doesn't take into account everything else in the reaction mixture (GABA, NaNO2, HCL) so your ability to stir will decrease with the more reagents you start with.

For example, without vigorous stirring the addition of HCl with a pressure equalized addition funnel running outdoors with an ambient temperature WITH an ice bath of -5 / -3º C reached a maximum temperature of 2º C with LITTLE evolution of the orange gas (this took about four hours or so). After the addition was complete and the flask removed from the ice bath the flask was shaked and inmediately the temperature of the reaction mixture rose to 10º C, it fizzed and bubbled perhaps indicating that the reaction had not gone to completion and unreacted excess HCl was present.

Regarding the distillation

You people are trying to distill using water/steam baths, this is downright impossible as the heat transfer from the liquid/steam to the flask is inhibited by the evaporation water, you cannot transfer heat from a volatile medium TO THE SAME MEDIUM YOU ARE TRYING TO DISTILL.

Easy fix to distill the mixture in an oil bath, olive oil works, it's not the cheapest method, you might be able to use vegetable oil. The oil won't fizz or crackle as long as there is no water in the bath.

For those of you who have Liebig condenser, you can simply use a fishtank water pump and vynil tubing to keep the condenser cool.

Now for some question of my own:

What is the consensus on the pH's for the reaction? After distillation it appears no one is obtaining SOH's 4.1, then again that is a 10 mol batch which I assume no one else here is performing.

Fine, some posts back SOH indicated that post-reaction mixture was basified to pH 6 to keep "the salt level at a minimum". There's two things about this notion that concern me. If we are simply trying to raise the volume in the distillation flask why not use water, hell why don't we try and push the equilibrium towards the lactone (GBL) instead of trying to form GHB.

For treatment of the distillate:

What's the consensus on the pH needed before boiling down the water?

If you refer back to the article: (READ THE DAMN THING)

http://www.erowid.org/archive/rhodiu...sic.issues.pdf

Page 1319 states: In a pH 7 buffer the relative proportion of GHB after five days was AT MOST 15%. However at pH 12 the relative proportion of GHB was close to unity after twenty minutes or so.

So, my theory is that people are distilling an equilibrium mixture thus rising the low-yields, basifying to pH 6 is actually making this worse than it should be.

Last note:

The paper here is the conversion of glutamic acid (5 carbons long, two carboxylic moieties) to the lactone. This is entirely analogous to the GABA/GHB conversion.

http://www.orgsyn.org/orgsyn/orgsyn/...&prep=cv7p0099

It states (with a 70% yield): 2.

The addition requires about 30 min. During addition the reaction mixture should warm to 30–35°C and smooth evolution of NO2 and N2 should occur. If the solutions of NaNO2 and H2SO4 are added too rapidly, more gas appears to be generated and a reduction in yield occurs.

and

The title compound has also been prepared11 using hydrochloric acid instead of sulfuric acid, and ethyl acetate instead of acetone. In the hands of the submitters, this procedure gave a lower yield.

Thoughts?

[sigma462]

Alright you crazy people, a bit of experimentation and voila.

So as far as the cooling goes, as long as there isn't noticeable evolution of the orange gas the reaction should proceed just fine. I've monitored the reaction and 5 Celsius has been the highest temperature to run the reaction safely.

Now, for the distillation. Read my previous post, you want the pH at 2-4 ( I haven't found a lower limit for this. However you want to add the acid long before you start so the product is ints cyclic form.

If you distill at low pH you don't get elimination of the alcohol functionality and thus you don't get stinky butyric acid in such large proportions. Note elimination occurs both through acid and base catalyzed mechanisms. I haven't had to boil in charcoal any more.

In respect to the yields: at high pH ghb interconverts to GBL to reach equilibrium in a 68:32 ratio. This is why you have to distill several times - not because of the azeotropre forming.

I'll post some pictures of the product in a bit, its colorless and odorless and pretty darn potent.

Much love