• Neuroscience & Pharmacology Discussion Welcome Guest
    Posting Rules Bluelight Rules
    Recent Journal Articles Chemistry Mega-Thread
    FREE Chemistry Databases! Self-Education Guide

  • N&PD Moderators: Skorpio | someguyontheinternet

mephedrone long term negative effects progress reports

well ive had plenty of fun with it, been experementing for a few months now, never over 500mg in a sitting though and i always leave a decent amount of time between uses (usually only at weekends unless something special is goin on in the week) so far the worst side effect i had was on my 2nd dose when i had a very dodgy stomach the next day, feeling queasy all day, but no worse than a heavy night on the booze, havent seen any side effects in any of my mates either, its nearly all gone now though and once it is i shall move on to the next thing that takes my fancy, but i too think most of the bad side effects are down to people either being stupid with it, taking big doses or people who are probably having a bad reaction to it
 
quanta- out of curiousity where did you get the impurity of 3-methylmethylcathinone? I honestly don't know but looking at the molecule i would assume the chinese are going from the 4-methylpropiophenone so i have a hard time understanding how 10% of the 4-mmc would be 3-mmc? And, duh, i thought we have already been thru the toxicity of 4-substitution (PMA? PMMA?) and of methylcathinone........and you combine the two? I sure as hell aint fucking with this shit......
 
amanitadine said:
quanta- out of curiousity where did you get the impurity of 3-methylmethylcathinone? I honestly don't know but looking at the molecule i would assume the chinese are going from the 4-methylpropiophenone so i have a hard time understanding how 10% of the 4-mmc would be 3-mmc? And, duh, i thought we have already been thru the toxicity of 4-substitution (PMA? PMMA?) and of methylcathinone........and you combine the two? I sure as hell aint fucking with this shit......
Click to expand...

I know there is not to be discusion on synthesis but hopefully this will be ok. The most likely precursor for mephedrone is 4-methylpropiophenone which when produced by standard methods or purchased from chemical suppliers contains up to 10% 3-methylpropiophenone (technical grade reagent). Separation of 3-methylmethcathinone from 4-methylmethcathinone is difficult. On large scale, multiple recrystallizations are required which I doubt most RC manufacturers would do because of lost material and thus lost profit - hence the impurity. I am suspicious of numerous RC purity claims.

Separation of 3- and 4-methylpropiophenone via distillation is pretty much impossible.
 
Last edited:
Nah it'll be most probably fractional distillation under reduced pressure (same way of purifying safrole from plant sources) for separating 3-methylpropiophenone from the 4-methyl (or are the boiling points within a few degrees of each other ?). One way of ensuring purity is to start with 4-methylbenzaldehyde and treat with a grignard, then oxidize to the ketone, but that would be prohibitively expensive


I am suspicious of numerous RC purity claims.
Click to expand...

I think they just make the numbers up as they go along.... "mmm 98 percent, that sounds convincing - slap that on the label" (only in Mandarin! =D)
 
Sounds like the type of thing that you do and forget about and then when your 35 keel over from a massive heart attack due to damage to your heart valves and circulatory system, just because it don't kill you right then don't mean its not setting you up for some irreversable damage.
 
fastandbulbous said:
Nah it'll be most probably fractional distillation under reduced pressure (same way of purifying safrole from plant sources) for separating 3-methylpropiophenone from the 4-methyl (or are the boiling points within a few degrees of each other ?). One way of ensuring purity is to start with 4-methylbenzaldehyde and treat with a grignard, then oxidize to the ketone, but that would be prohibitively expensive


Yep, boiling points of 3- and 4-methyl are very close to one another, you may get rid of some but not all. And you are correct about your other proposed route - better selectivity but much more expensive.

Dread - Chromatography works but only on a small scale not production scale.

http://www.sigmaaldrich.com/catalog...ALDRICH&N5=SEARCH_CONCAT_PNO|BRAND_KEY&F=SPEC

Check out what the remaining 10% is under the description...
Click to expand...
 
Last edited:
fastandbulbous said:
Would column chromatography a la LSD not be a viable method for separation (probably better with he final products as amines can be differentiated by differing pH elution)
Click to expand...

Chromatography works great but it is prohibitively expensive for any scale greater than say 50 grams. Chromatography grade silica gel is very expensive and its use is always avoided in production chemistry. For production, distillation and recrystallization are really your only choices especially when you are dealing with a relatively cheap product.

I should point out that I have not tested commercial mephedrone for the 3-methyl impurity because I've never purchased any but I am only pointing out that it is a very likely impurity based on personal experience in its sythesis and where it comes from
 
Last edited:
I would be suprised if it was 3 methyl rather than 2 methyl given the way it is made from toluene, where the reactive positions are ortho which is sterically hindered and para which is not, hence the para product predominating under kinetic conditions.
me thinks sigma may have written a 3 instead of a 2 and this has become net lore, with nobody bothering to check what seems to be an odd feature.

see the pharmacopeia data and DMFs for tolperisone which is made from 4-methylpropiophenone.
 
^ I got to admit, para & ortho substitution go togehter like salt & pepper, meta tends to be a different thing altogether. I gather 4-methylpropiophenone is from a Friedel-Craft acylation of toluene (that'd be my first approach)
 
vecktor this was exactly my line of thinking, i assumed a 2 and a 4, and if they are making the shit this inexpensive it has to come from our fav cheapo hydrocarbon amenable to substitution. but i dunno, I'll stand corrected. And yeah, running column chromatography on even 10 grams of anything is a total time consuming bitch and fractional distillation useless if the b.ps are as close as quanta implies. So i dont doubt the large presence of an impurity, whether 2 or 3 or whatever......I mean, these guys are RETAILING the crap for a couple bucks a gram, I'd be suprised if their even is a recrystallization involved. I have a feeling we will see a fenfluramine like rash of heart valve problems down the line or something similiar. I tried it one evening, and the physical effects were pronounced and of concern but i swear I could even *feel* my neurons sizzling......that was enough for me!
 
Methyl groups are so weakly 2,4-directing that with weak electrophiles like oxonium ions you will get a percentage of 3-substitution. The late transition state in the reaction will favor the 3- and 4-position (In this case about 90% para, 10% meta). Too much on this topic to elaborate here but look into product distribution in acetylation or nitration of toluene. In Aldrich's product it is the 3-isomer. As you say though, dangerous product no matter how you slice it.

Nitration of toluene at 85C: 58% ortho, 4% meta, 37.2% para (Strong electrophile)
Acetylation of toluene at 25C: 3% ortho, 69% meta, 28% para (Weak electrophile) unexpected hey? If you increase the temperature further, the amount of meta product will increase even more. Thus, control of the conditions in acylation reactions with toluene is very important and on on large scale, this becomes more and more difficult unless you really know what you are doing and my guess is that they (insert weird lab name here) don't.

Only the gist of what is said in undergraduate organic chem texts is true, check out http://www.amazon.com/Mechanism-Theory-Organic-Chemistry-3rd/dp/0060440848 if you want to know more
 
Last edited:
Quanta said:
Methyl groups are so weakly 2,4-directing that with weak electrophiles like oxonium ions you will get a percentage of 3-substitution. The late transition state in the reaction will favor the 3- and 4-position (In this case about 90% para, 10% meta). Too much on this topic to elaborate here but look into product distribution in acetylation or nitration of toluene. In Aldrich's product it is the 3-isomer. As you say though, dangerous product no matter how you slice it.

Nitration of toluene at 85C: 58% ortho, 4% meta, 37.2% para (Strong electrophile)
Acetylation of toluene at 25C: 3% ortho, 69% meta, 28% para (Weak electrophile) unexpected hey? If you increase the temperature further, the amount of meta product will increase even more. Thus, control of the conditions in acylation reactions with toluene is very important and on on large scale, this becomes more and more difficult unless you really know what you are doing and my guess is that they (insert weird lab name here) don't.

Only the gist of what is said in undergraduate organic chem texts is true, check out http://www.amazon.com/Mechanism-Theory-Organic-Chemistry-3rd/dp/0060440848 if you want to know more
Click to expand...

I am sorry I just don't buy the numbers for the acetylation of toluene, from first hand experience of acetylation of the very similar ethylbenzene with 1 equiv AcCl and 2.5 equiv AlCl3 it is para approx 90 meta 2-3% and the rest ortho. overall conversion about 45%. perhaps if the reaction is pushed harder a different distribution occurs I don't know. (product identification by 1H nmr and IR between 1900 and 2400 cm-1)
if you have a primary ref giving the reaction conditions for producing the meta isomer as the predominant product I would appreciate it as it would be a useful thing to be able to do.

quick look found this http://pubs.acs.org/doi/abs/10.1021/ja00754a045 mostly para with some ortho and met being a minor minor product
 
Last edited:
vecktor said:
I am sorry I just don't buy the numbers for the acetylation of toluene, from first hand experience of acetylation of the very similar ethylbenzene with 1 equiv AcCl and 2.5 equiv AlCl3 it is para approx 90 meta 2-3% and the rest ortho. overall conversion about 45%. perhaps if the reaction is pushed harder a different distribution occurs I don't know. (product identification by 1H nmr and IR between 1900 and 2400 cm-1)
if you have a primary ref giving the reaction conditions for producing the meta isomer as the predominant product I would appreciate it as it would be a useful thing to be able to do.

quick look found this http://pubs.acs.org/doi/abs/10.1021/ja00754a045 mostly para with some ortho and met being a minor minor product
Click to expand...

Yah, I'm not doubting your results infact I have attained similar results. I guess my major point is that acylations of alkylbenzenes can be unpredictable and can be condition dependant. Further, separation of the 3- and 4-isomers can be difficult if need be. I just don't trust anonymous labs to perform multi-step synthesis of compounds meant for human consumption. Cheers. :)
 
Quanta said:
Yah, I'm not doubting your results infact I have attained similar results. I guess my major point is that acylations of alkylbenzenes can be unpredictable and can be condition dependant. Further, separation of the 3- and 4-isomers can be difficult if need be. I just don't trust anonymous labs to perform multi-step synthesis of compounds meant for human consumption. Cheers. :)
Click to expand...

all interesting.
I suppose analysis of commercial mephedrone is required gc should separate the isomers reasonably well.
V
 
You must log in or register to reply here.
Top