Wacker impurity ending up in final product?

[ja304]

It was stated by someone that the Wacker Oxidation reaction results in 15% aldehyde, 85% ketone.

Do I have the correct understanding of the implications of the Wacker products?

If Wacker products contains an aldehyde of only 5-10 degrees difference in bp compared to the ketone, then it is nearly impossible to achieve separation under a vac. dist. procedure.  Since aldehydes form imines more readily than ketones, (which both proceed to form amines) the undesired impurity cannot be separated by an A/B, and certainly not by distillation since the bp would be too close as well.

My point is: the aldehyde impurity from Wacker reactions form an propyl amine impurity that appears to be unavoidable and unseparable. 

My questions are: 1) Am I missing something?  2) Is this an impurity that is part of life and inescapable?

[supernate]

ive never heard that aldehyde jazz before (but that dosent say alot). do you have a ref. for that, of was it just in passing conversation? to test this, take a sample of your honey down to your old university lab and run it through GC and IR and try to see if A- there is a close impurity, and B- it is a phenylpropylamine and C- if the PPA is good/bad/neutral to your health and your high.

[Rhodium]

A mild oxidation of the reaction mixture, using something like MnO₂, K₂CrO₃ or similar (

UTFSE for ""aldehyde AND oxidation""

), will not affect the MDP2P but will oxidize the aldehyde to MD-Phenylpropionic acid, which in turn can be easily removed by a simple bicarbonate wash.



The amine gotten from reductive amination of the aldehyde ("MDP3P") would be 3-(3,4-Methylenedioxyphenyl)-propyl-methyl-amine, and while it probably isn't very psychoactive at the dosages involved, it may have toxic effects, so to do your fellow human beings a favor, clean your conscience - clean your ketone.

Distillation of the freebase gotten after an acid/base extraction of the Al/Hg reaction mixture, followed by recrystallization of the precipitated HCl salt will probably help removing a majority of the above impurity, but it does not beat the oxidation + base wash suggested above to remove it completely.

(09-09-04):
The boiling point of MDP3P (MD-Phenylpropionaldehyde) is 104-106°C at 0.3mmHg [Ref: Synthesis (2), 151-153 (1980) and Tetrahedron 42(20), 5515-5522 (1986)] while that of MDP2P (MD-Phenylacetone) is 100-110°C at 0.2 mmHg [Ref: J. Anal. Tox. 6, 71-75 (1982)]. As the substances essentially shares the same boiling range, there is no use even trying to separate them through distillation as they will always distill as a single fraction.

[raffike]

Yeah,it sounds pretty easy to remove this contaminant but i haven't heard a single report on this oxidation and i probably won't cuz it lowers the "yield" at least 15%

[Rhodium]

I wonder how one could make people understand that they aren't getting a 15% lower yield, but rather a final product which is 1.18 times stronger (as they aren't consuming 15% of filler, which in the best of scenarios is "inert", and which might even be toxic?).

There is one thing which is good news though - the 85:15 ratio stated before is for the O₂ Wacker, while most people here make use of the BenzoQuinone Wacker. I have references on my page for BQ Wackers which are very ketone-selective.

[supernate]

so the O2 wacker is your reccomendation for best yields? what about the acid catylised p-benzo wacker? how do the actual experimental yields compare?

N

[scram]

Ate 1 gram of that "mystery powder" that has come out ~6% of reactions. Did nothing. I supposed this was the aldehyde. The only difference between taste of it and the real deal is that it produces a cooling sensation when put on the tongue. Absolute useless stuff.

[hCiLdOdUeDn]

Dont you care about your body/mind?! Treat it better than you would treat GOD! Eating 1gram of mystery powder can kill you!

I fully support and agree with Rhodiums ideas on purifying and isolating compounds and make sure you work with pure chemicals every step of the way!! Why would you want to injest an "unknown powder"!! This is what makes bad chemists look like white trailer trash meth makers. You dont want any impurities getting into the consumers/buyers. If you do sell your product, you better make damn sure its something its as pure as possible.

[raffike]

I don't think this product is toxic but that doesn't mean you should eat it.Well now we know that it's not CNS active.

[Rhodium]

How did you isolate that "mystery powder"?

[scram]

No need to isolate it. One time there was ~14 grams of it with very little if any mdma in it. I was previously thinking maybe some mgso4 got thru the filter into the wash process. No way, not 14 grams worth. I always made sure the actone was clear before separating the mgs04 too. It has a different consistency when acidified from the toluene. Crystalizes slightly different and is more light, powdery, more white. Also seems to settle/crystalize last in a acetone solution in the freezer for days. Leaving a whiter, silt-like layer on top. I've noticed that when it did happen it was concurrent with too high al/hg temps (above ~65C) or too much water in the al/hg or possibly too much nitro. Another observation was from a wacker than just didn't run normally (heat spike was too short or too hot). These were just human observations and not scientific evidence like you rich boys have with your GC/MS toys.

[runne]

Sounds EXACTLY like what happened to someone I know. Read post #

Post 433342 (missing)

(runne: "Bioassay Failure? What did SWIM produce?", Newbee Forum) .

SWIM was VERY excited when the entire beaker just FLOODED into crystals   

Oh well, hasn't happened again so SWIM expects that it was something that came over from the Al/Hg (probably not good for human consumption!) Since SWIM also used MgSO4 as a DRYING AGENT for GASSING.. could there be a connection? Does MgSO4 react with HCl gas in any way?

Runne

[scram]

Does someone have the density of this stuff: 3-(3,4-Methylenedioxyphenyl)-propyl-methyl-amine

I've looked for months without finding any sources to information on it. There were times that I remember my ketone matrix weighing 1.214g/ml and 1.2

[cublium]

I have references on my page for BQ Wackers which are very ketone-selective.
Could you give me a link if you still have em.And what about such impurity as propiophenone?Some documents say O2 wacker sometimes(depends on substitution etc) yield propiophenones along with methyl ketones,how are things with p-B?