01-18-02 12:04
No 258012
While doing a little experimenting, someone has noticed that if an aqueous acidic solution of HgCl2 is used in place of crystalline HgCl2, the reaction goes much nicer. Someone experienced no boiling up or what might be considered a runaway reaction. If someone else could give this a try to verify, I would bee glad to hear.
crucify the ego before it's far too late
and you will come to find that we are all one mind
(Hive Prodigy)
01-18-02 12:37
No 258027
noj, you know the routine, we need more details. What reaction? MD-P2P/MeAm? Or MDP2P/MeNO2?
Amount of water? Procedure? More details?
PrimoPyro
Vivent Longtemps la Ruche!
(Distinctive Doe)
01-18-02 12:46
No 258031
What do you mean?
I think you need to explain what your talking about a little better.
Well it took me a while to post and PP beat me to it.
Thats what happens with multiple windows open.
NoJailForPot (http://www.nojailforpot.com/)
(Hive Addict)
01-18-02 12:51
No 258035
I really need a notebook
Someone made some HgCl2 solution according to Zygoat, and kept this in the acidic solution without evaporating. This person finds it easier to handle fluids than powders.
Performing the amalgam, this person followed the MethylMan writeup. He then added @ 30mL of this dilute mercuric solution. No NaOH was added, to keep it acidic. Amalgamation was nearly complete, Al was grey and not too much shiny surface remained. Nitro/MDP2P/MeOH was dripped in at 1 drop a sec. Within 5-10 minutes, solution became hot, but never to the point of foaming. Reflux began @ 20 minutes later with gentle heating now applied. Addition complete 30 minutes.
Someone read that the addition of NaOH encourages the breakdown of Al. Since foil was used, he didn't want it to be encouraged. So acidic solution was used. Al completely dissolved within an hour. Continuing reflux for 3 hours.
These results are repeated by this person, but would like another testimony just to make sure it's reproducible.
crucify the ego before it's far too late
and you will come to find that we are all one mind
(Hive Bee)
01-18-02 12:51
No 258036
Well I forgot where, but I once read somewhere that the Al/Hg reaction proceeds better under acidic conditions and basic conditions hinder the reaction. I could be wrong though. Maybe your acid is reacting with the Aluminum hydroxides helping keep the pH down.
(Distinctive Doe)
01-18-02 13:00
No 258042
Did it work?
And was the yeild good?
NoJailForPot (http://www.nojailforpot.com/)
(Hive Prodigy)
01-18-02 13:08
No 258044
Highly interesting....
But wouldnt the acidic protons react with the methylamine, forming the methylammonium ion and an anion?
PrimoPyro
Vivent Longtemps la Ruche!
(Hive Addict)
01-18-02 13:30
No 258051
Yeah it worked like the typical MM reduction. Yields were similar.
I like that nojailforpot.com
Needs to be expanded to any victimless non-violent non-destructive offense.crucify the ego before it's far too late
and you will come to find that we are all one mind
(-)
01-18-02 14:01
No 258057
amalgum, that is not a universal truth. Acidity in oxime and nitroethane redxns is neccesary (period). I've done this using GAA, HCl and silica gel. GAA being the highest yeilding. I'm not convinced that are reductive amination of ketones would benifit from acidic conditions. Otherwise we would just toss in MeAM.HCl, without freebasing it first.
(Stoni's sexual toy)
01-18-02 14:31
No 258065
How much acid did those 30ml contain?
I bet the reaction was acidic for the first few minutes only, as soon as the Al started to react and some nitromethane was reduced to methylamine the whole reaction was basic just like any other Al/Hg amination.
(Hive Addict)
01-18-02 15:08
No 258077
Os, that may be true. It was around 8% HCl (25% of 32% Muriatic) so perhaps it slowed the reaction in the beginning. Someone will test the pH throughout next time. It definitely seems to control the volcanic part of the reduction though.
crucify the ego before it's far too late
and you will come to find that we are all one mind
(Junior Service Representative)
01-18-02 17:50
No 258153
As long as one has the condensor power to contain it, is there such a thing as adding the nitro/ketone too fast(exothermia damper yields?)?
PB
"A taste of honey is worse than none at all"
~ Sublime
(Hive Bee)
01-18-02 20:31
No 258204
SWIM has found that almost running the amalgam as a pressurized rxn keeps the reaction mellow and improve yields. SWIM puts a straight vacuum adapter on top with the handy balloon and then fits a blowout valve on the nipple set for 12psi just under what the glassware will hold. The whole reaction is screwed clamped together using safe-loc setup. Its been safety coated and is nice and securlly wrapped. When the reaction gets running volcano style or if it starts to bubble up the condensor slow squeezing of the balloon to force some of the methlyamine back down the condensor that didnt condense seams to stop the eruption but keeps it bubbling like mad in the reaction flask. Havnt had one runnaway yet. And SWIM can preety much add the MeNO2/Ketone mix at a extremmly fast pace.
Hmm What would be the side rxns of running an amalgam in a pressure vessel be? Hydrogen is released as a side product in this and is completly useless. Would keeping it in the reaction vessel cause bad or explosive side effects? The only gasses escaping here are hydrogen and methlyamine? At least that would get past youre condensor. Or would the water formed from the amalgation become excess if it is a closed system and ruin the rxn. Or how about adding the methlyamine as a gas as the reaction progresses sort of like a hydrogenation. SWIM has a Teflon coated vessel rated to 100psi that would probally be perfect for this.
Looking for that one pot-just add and let go-high yielding syth. For the lazy bees. Damn looks like SWIMS going to be breaking out the hydrogenator again. Been itchy for some old fashioned hydrogenations again.
(Chef d'Equippe)
01-19-02 04:01
No 258292
Hey NoJ, Baal knows exactly what you're talking about. Baal has some of that same solution you speak of, that he has been playing around with once again lately just like yourself. Baal has used it in the past a couple times in a pinch, but normally dried it to crystalline prior to use. Baal has found that a small 'scoop'(~100mg)(3-4 drops) of the granular white liquid is all it takes to kick out a normal Al/Hg/Nitro reaction. It doesnt make the reaction acidic, theres not enough acid in volume to do that. Its basically just wet HgCl2, if it does change the reaction Ph then youre adding quite a bit more than necessary. Baal can tell you from experience, this stuff can and will produce a volcanoe if given the chance. Baal took an accidental Al/Hg shower last week for 2-3 mins. or so, great for the complexion. Baal adds a small amount of MeOh to the white,HgCl2/H2O liquid to help dissolve some of the more chunkier stuff with it. Dispensing with an eyeroppper is a much simpler task I agree. Baal never posted anything on this because Baal figured someone would flip him some shit about being too lazy to dry his HgCl2. Glad to see that someone else enjoys it just the same.
GODISNOWHERE
(Stoni's sexual toy)
01-19-02 15:19
No 258457
blatztoff:
why make this goddamn procedure any more complicated than it really is???
Is 90% yield not good enough for you or what?!? Sheesh!
(Old P2P Cook)
01-19-02 16:03
No 258469
Baal never posted anything on this because Baal figured someone would flip him some shit about being too lazy to dry his HgCl2. Glad to see that someone else enjoys it just the same.
Yeah, for the purposes here it is much better (safer) to not try to isolate the solid mercuric chloride but just keep it in the acidic solution and dispense it this way, in liquid form.
(Chef d'Equippe)
01-20-02 00:27
No 258611
No doubt Terbium, the less hands on with that crap the better. It also kinda opens a door for the newbee that needs some HgCl2, but is still rusty in the synth area or has no other access to it. It is so easily made w/otc's and doesnt require much in labor, boilin', filterin' & a little mixing is about all.
GODISNOWHERE
(Stranger)
01-27-02 15:19
No 261562
I probably don't understand this process as well as I should and have had very little success with it, but as I understand it as the Schiff's Base. I also read that this reaction requires acidic conditions. Between 4-6 if I remember what I read correctly. I can't quote that source right now (or at least not the author) but it was simply an Organic Experiments book my sister-in-law let me read. My guess is that basic conditions only give the appearance of a sped reaction because of it's reaction with the Al, which I would like to remind everybody that it does without the presence of Ketone or MeNH2. In the presence of H2 (this is just a guess) the solution starts to proceed to the lower ph on it's own. Adding NaOH, I suspect, just slows down the reaction we want and creates a mess. I used MeNH2 and probably screwed up there. Again, I've had little sucess with this and would probably have done better if I would have listened and used Nitro. In the words of Joe Dirt, "I'm new, I don't know what to do!" In other words, this is my first post on the hive so take it easy on me if I'm wrong.
(Hive Bee)
01-27-02 21:44
No 261718
I don't get the VOLCANIC part of this. Pinky has done many al/hg rxn's in beakers, flasks, rxn kettles and with minimal condensing paths (sometimes none) and even had drip rates as high as 8 drops per second and the reaction never bubbled out of the beaker or up and out of the condenser. So what is it that causes this happen? As the only thing that I can conclude to cause it is the heat put of from the addition mixture reacting with the foil at high rates causing the surrounding meoh to boil and as the heat has no where to go if the reaction is still paced as is then the meoh is forced out, causing "the bubbling over affect". So why hasn't this happened to pinky? As he would like very much to avoid this.
(Stranger)
01-28-02 13:34
No 261946
I've been using the methods set forth in brightstar's writeup. In case your not familiar, there is no MeOH used and amalgam is done with water prior to dripping in MeNH2 and ketone (both in IPA solution). As a matter of fact, they're not dripped in at all, they are simply added.
Here's my point. I've had it boil over. That's only Al, HgCl2 and H2O. Evidently this does not involve the reduction of alcohols (if it did we would all be using Al/Hg to reduce Ephedrine). I that the lack of vigor is probably due to pour amalgamation (i.e. bad or insufficient amounts of Hg Salt). When it has boiled over, I believe that their was an excess of Hg Salt. The eppervescence is caused, I believe, by H2 produced during the process. This is after all a reduction, which gives off H2. I would be concerned more with lack of a reaction more than too much of one. Next time I'm going to set up a reflux (which was not mentioned in the Brightstar writeup), make sure that I have a good amalgamation in progress and then start dripping in ketone/Nitro in MeOH so that I can nail down all these question I have about this procedure. I certainly have not obtained good yeilds (sometime none at all) and look forward to seeing the fruits of my labor. In the meantime, chemistry is still more fun than just about any other investment of my time and money.
(Hive Bee)
02-01-02 02:23
No 263726
Man what the fuckk?
"In case your not familiar, there is no MeOH used and amalgam is done with water prior to dripping in MeNH2 and ketone (both in IPA solution). As a matter of fact, they're not dripped in at all, they are simply added."
HENCE THE REASON YOU HAVE SHIT ASS YIELDS.
You obviously have not done this procedure correctly. Nitro redcutions and brightstars meam though good but seriously outdated yielding only a mere few grams form 50g ketone HAH, Are not carried out the same.
You mention the preparation of amalgum ad the water and al/hg for storage purposes in certain liquids if you'd rather have pure al laying around instead of hgcl2, and meoh is present with NO (or very little~5%)water when you do this readction with the amalgamation preceding it in the same container with no washings. Meoh, hgcl2, al simple it bubbles gets dull and foggy and boom you ad your shit. Yea go ahead and dump 50ml of nitro and 75g of ketone into the flask at once and you will bath in it. I would rafrain from saying what I don't know what I'm doing when who I've tought is getting high eighty to low ninety percent yields.
You wonder why you don't get the fruits of your labor? Then wake up and figure out how to do it correctly!
../rhodium/clandestine/gonzo
Follow this and you may have better luck.
(Stranger)
02-01-02 11:28
No 263882
I think your under the impression that I was accusing you of not knowing your shit. Never meant to imply that. I've read my post a couple of times and still don't know how you came up with that idea. You mentioned not getting a volcanic reaction. I too got no such reaction. However, you didn't really specify which method you were using, so I simply told you which one I was using. I know the difference between the methods in the BS write-up and those set forth in the MM write-up. That wasn't my point. I was merely concurring, to a point.
To the point. Unless I read it wrong, I did the amalgamation correctly. In the BS write-up I had (possibly out-dated) you start with water and do wash before MeNH2/Ketone in IPA are added. Pretty sure the copy I had stated just that (I've read it a hundred times). I now realize, through trial, error and advise recieved on the Hive, that it's supposed to go down like you said. Thanks for the advice, I really do appreciate it, I don't take myself too seriously and never meant to imply you don't know what your talking about.
By the way. Didn't this discussion start out on the topic of Acidic Amalgamations? There are certain problems presented if your doing this with MeNH2.HCl and having the mixture acidic, but my textbook understanding of the process would tend to point me in the direction of an acidic solution.
(Hive Addict)
02-01-02 13:51
No 263942
moriarty, if you can just dump in your ketone, then it isn't ketone.
I've also used HgCl2 still in the water it was made from to fuel an Al/Hg reaction, and it ran quite smoothly. I didn't think it had anything to do with the acidity though, I think it had more to do with the few drops of excess H2O helping to cool the reaction and to provide water for the formation of aluminum hydroxide and free hydrogen to reduce the imine to the amine. Without these few drops of excess water, all of the water required in the reaction will have to come from the ketone to imine formation.
OK, I guess that didn't make much sense after being written down. But I know what you're talking about.
If Pacman had influenced us, we'd run around dark rooms eating pills and listen to repetitive music
(Newbee)
02-01-02 15:07
No 263972
I think there is a difference between the process when MeNH2 is used as opposed to MeNO2. That's what synthomatic was saying and that is what is indicated by comparing the MM write-up to Brightstar's. What you wrote did make sense and I agree, it doesn't go very fast when the only H2O in the picture is that produced by imine production. Thanks.
(Hive Bee)
02-01-02 23:48
No 264143
"In case your not familiar, there is no MeOH used and amalgam is done with water prior to dripping in MeNH2 and ketone (both in IPA solution). As a matter of fact, they're not dripped in at all, they are simply added."
As for all amalgamations I have noticed on pinkys results that any reaction where the hgcl2 was dissolved in water or meoh and the al allowed to react prior to reaction and replaced with fresh solvent with ketone later added, a substantial loss in yield was incurred (even in the calssic BS). Even with meam there are better higher yielding ways than the bs writeup. He gave a working method for the non-chemist for fun based product not high yielding street slinging tweaked procedure.
(Stranger)
02-02-02 02:49
No 264172
I don't even claim to be highly knowledgeable on that subject but I think that the lower yeilds would have more to do with the timing of the amalgamation and the timing of the drip..... I don't see why the acidic solution would hinder the reaction and i'd imagine that having it in this medium would allow for better dispersal of HgCl2 around the Al for amalgamation. I dunno that just seems logical.
Flip
(Hive Addict)
02-02-02 03:15
No 264174
Acidic conditions ruin yields.
This is my theory: the methylamine forms the more stable methylammonium salt and will no longer act as a good nucleophile and will not attack the carbocation of the ketone (protonation of the carbonyl, one would think would improve reactivity... but it doesn't seen to, the more important, reaction limiting step is making the methylamine a good nucleophile and not making the carbonyl a good electrophile). Bright Star's yields suck because he does not add enough BASE to his reaction to turn the MeAm.HCl into MeAm. The general idea of Bright Star's method is, in my humble opinion, superiour to Methyl Man's. I've tried them both, and prefer (and gotten better yields from) BS (... but done in MeOH with 1 equiv base and a toluene extraction).
Both methods work, and what I think should decide if one uses MM is if the reaction size is small and it's a relative pain for you to produce methylamine. (but if your reaction is big or it's easy for you to produce methylamine, try Os' approach... you won't be disappointed)
(Hive Bee)
02-12-02 01:54
No 268495
ANTIBODY. DOES THER AL HAVE TO BE PREPARED SEVERAL TIMES WITH WITH A RXN LIKE THAT OR CAN IT BE DONE ALL AT ONCE AND THE AL JUST SCOOPED OUT OF THE POT AS NEEDED. THE hG IS ONLY REMOVING THE OXIDES CORRECT IT IS NOT AFFECTING THE ELEMENTAL AL.
VL_
(Chief Bee)
02-12-02 02:25
No 268510
VL: Please check your caps lock status before posting a message. That post was really ugly.