posted 12-24-1999 07:02 PM         

Could I get a little help? Mr. Agidk had a terrible day. He fucked up, plain and simple. Something so obvious went unrealized due to fatigue and as a result he was trying to gas toluene/product solution that moisture was inadvertently allowed to infiltrate. So any new bees reading, pay attention, and avoid this pitfall.

Late at night, after drying his solution with MgSO4, he was tired and decided it was too late to gas it so he sealed it in a big flask and put it in the refrigerator overnight.

THE FRIDGE!!? Yes, the fridge, that wet chilly place where moisture can condense through (yes, pass through) glass containers. It didn't even hit him that further moisture might go through the glass. That's what he believes happened. It has to be. Is this a common error?

So in the morning, he got all set up, started gassing, and got nothing but overacidified orange solution. This was a biggee too (for him), as he was expecting around 30g raw/24-26g recrystallized and needed this one to happen.

To make matters worse he then checked the pH and it seemed to be 1 (!!) or so, so in a fit he decided to add a little bit of base to bring it up to more like 4 or so, wherever it usually is when crystallizing. I don't know what he was thinking, maybe he was going hoping more would precipitate in the freezer if he did this. He wasn't thinking rationally by then because he was pissed at himself. Anyway, the pH didn't even change after he put in in there. (It was about 2 grams of NaOH in about 30mL water, and only a few mL of this was poured in before the idea was abandoned.)

Now there is some goop in the bottom of the container that may be the base crap or may be product, he's not sure. It looks like the same amount of NaOH that he put in there, but why would it sink and stay separate? He'd like to separate it out of there if that's what it is. He made a similar mistake several months ago and was able to recover some product by leaving it in the freezer for like 2 weeks. It crystallized as orange crystals on the side of the container.

This time though, he wants to recover it sooner. What are some suggestions along the lines of distilling off the toluene and letting it crystallize in the flask? Or other variations? Is it okay to leave it pH 1 to do this?? Can I get some suggestions? Please?!

posted 12-24-1999 09:15 PM         

Okay, here we go.

First, you need to know that this has happened to SWINM (someone-who-is-not-me) before. He made the same mistake in allowing moisture to condense in his flask by leaving the whole kit and kabootle sitting in an ice bath presumably too long. Whether it was condensed water that was the culprit or something else, who knows? The fact of the matter is, each time this mistake was made, the whole isolation proceedure ended in failure with only the red oil precipitating out as the final product.

Sometimes, in SWINM's experience, even with the cyano method of un-methylated amine production using ammonium acetate as the amine source, this red oil had to be dealt with. Usually, in that case, there was too much back and forth acidification to basification going on, and with each round, well, you guessed it, the red goop would form. So you may want to simply back-extract with dilute HCl and then basify, re-extract with solvent, dry, and then gas IMMEDIATELY to see what you get. I don't think that there will be any loss of product per se using this technique. I simply think that something about the way the product changes in composition (maybe it gets hydrated; maybe there is just enough decomposition to prevent crystal formation) promotes the good chance that it won't be suitable for isolation as the HCl salt. In fact, considering these factors, you probably will get the red oil again after all.

Since you DON'T have the time to wait for your product to crystallize over two weeks, I suggest you take an entirely different and radical approach that SWINM has only dreamt about but never had the guts to try (although after having attempted just about everything else, he now knows that it actually might have had a good chance of working).

Since most likely, the reason you can't isolate your product as a salt has to do with its being somewhat dirty (yielding the only the amorphous red oil upon gassing), I believe the solution to your problem lies in the state of purity of your product as a base. And therein lies the solution! Think about this Methyl Man, THINK ABOUT IT HARD!!! If you truly were expecting a yield of about 26 or so grams of product salt and the ONLY reason that you haven't gotten it is because you fucked-up in the gassing phase (allowing too much water to contaminate your solvent extract, etc. etc.) then it is logical to assume that you're product is still available -- it just simply can't be isolated through precipitation as its HCl salt. Sooooooooooo, I think your best bet is to basify your solvent solution (along with everything -- precipitated red oil and all) with a good 200 mL of 25% NaOH, shake to ensure that your entire solvent extract that was gassed before with HCl (when you fucked-up) is once again basic, wash with water several times, isolate your solvent/product fraction, DRY with anhydrous magnesium sulfate, DO NOT PUT IN FREEZER OR ICE BATH, and then gas? NOOOOOOO!!!! DON'T GAS!!!!

YES, you read right. Don't gas. Instead, distill your solvent off VERY CAREFULLY. Did you read correctly? YES, YOU DID! Distill VERY CAREFULLY. That means keep an eye out constantly. That means, use minimal heat and a good vacuum source. That means by being careful you won't fuck-up (at least this part of the process you won't). Now, when all the solvent is gone, see what you've got. This part should be interesting and frankly, I'm fascinated by the prospect of what you might find. Why? Because I've always assumed that whatever causes the red oil formation is always present to some degree just as the gassing phase is about to occur for the first time. I've always theorized that alot of SWINM's product is still in the toluene phase unprecipitated because of this equilibrium that exists (mainly existing on one end of the spectrum or the other due to impurites) between the clean salt phase and the red oil phase (sounds a little hokey and, in fact rather unproven is scientific terms, but you get my point). So needless to say, at the point right before gassing, I've been pretty curious about what would happen if SWINM evaporated all of the solvent. But to this day, he still doesn't know as when trouble came his way (red oil blues) he's always resorted to simplier and rather experimental novel crystallization techniques to remedy his problem which more often than not, just caused everything to end in failure. Keep in mind also that according to the original Ritter method, at no point after basification of the alcoholic solution with 35% NaOH is any attempt made to remove any NON-AMINE by-products or starting materials. From the alcoholic aluminum mess, one always just basifies with the 1000 or so mL of 35% NaOH without any effort to separate the amine products from the non-amine contaminants and this could also contribute to red oil formation for all we know. Anyway, enough of the ramble. Let's move on.

So now you've got your product, it should be an oil (presumably the base form of you-know-what). Try your best to isolate this amount by volume or weight to get an idea of how much is there. If you truly did everything else in your Al reductive amination correctly, then by all means, you should have your 26 grams of product in your flask (maybe slightly less as the salt weighs more than the base). So, now you wonder, what to do next? Here we go . . .

Distill your oil. For about 20 grams of suspected base product, use a 100 to 150 mL flask. Yeah, you read right. DISTILL IT!!! This is the only way that you can safely isolate your product so that it can be gassed in DRY solvent and crystallized to pristine purity. Don't listen to those other Hive members who will tell you, "Uh" duh "why don't you just try to make the sulfate?" NONONONONONONONO and NO. That is too experimental as you don't know about the many different factors that can come into play (like variable pH values). Vacuum distillation you DO know, Methyl Man. I know you do. And you know how to do it well. You know you've got that technique down pat as you are the one giving advice to othe bees about it. Time to trust your own skills. I know you can do it. And if it helps any, you've got nothing to lose. Might as well take that enormous first step towards the moon. Be a pioneer. Besides, what's the worst that can happen? Either the oil won't distill (which it should; if I remember correctly, it's BP is below that of the ketone) or it will. Either which way won't matter as by then you'll REALLY have gotten rid of all the water due to heat, so you can then dilute with solvent and re-gass if you wish. What else can go wrong? You could let the temp go too high and char your product in which case YOU SUCK AT DISTILLATION!!! But as you very well know, this isn't going to happen. You're going to vac distill and isolate you're product and when you have it, your going to gas and before you know what's happened, a nice sample of CLEAN and WHITE product salt is going to be sitting before you, and at that point, you're going to thank me.

End of story.

No stop crying and get to work. And most imporantly, go make Hive history!

I'm counting on you.

Your friend,

posted 12-24-1999 09:48 PM         

Yeah I know you're probably right that this is the best thing for Agidk to do. Are you sure about the amount of NaOH though? I worry about damage through overbasifying. There is already a bit in there but it's probably only equal to about a gram at most dry NaOH.

The other way to go I guess would what you suggested the last time he screwed up this way: leave it in the freezer for 2-3 weeks, and start on another round <sigh>.

Anyway PK, thanks, and I'll email ya because there is some other news (good news).

Wait---news flash. Just heard from Agidk, and he says that the shit is already crystallizing like crazy on the inside of the vessel, and pretty white at that, not red goop, and large chunky structures at that. Since it only took a half-day to do that, he knows that in just a few days to a week or so, there will be a shitload there to harvest, which he can then just recrytallize to purify.

posted 12-24-1999 09:54 PM         

Thanks Lord Buddha!

or should it be...

`Hail Mary-E, Mother of Phenethylamines'

posted 12-26-1999 05:43 PM         

So he separated that base shit off and put the remaining solvent/product/acid back in the freezer but doesn't expect much. He's writing it off as an expensive lesson. Still, he is glad when he learns something important like that and actually figures out what he did wrong. Evry fuckup is a lesson if you're able to make it one via good attitude and providing you know what happened.