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Methylphenidate >> Isopropylphenidate

Fornax55

Fornax55

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Jun 17, 2010
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It's frequently said (and from experience, seems legit) that drinking alcohol before consuming methylphenidate allows for the conversion of MPH into ethylphenidate. I have two questions regarding this -

is the metabolic process itself necessary to convert MPH into EPH, or would simply mixing MPH in a shot of high percentage alcohol do the trick?

More importantly, since typically ethanol is used for this process, would the substitution of rubbing alcohol (isopropyl) result in the conversion to isopropylphenidate? or would nothing happen? There's not a huge amount of data on isopropylphenidate and I haven't found anything relevant to this question.
 
Methylphenidate is enantioselectively transesterified...only the inactive ethylphenidate l-isomer is formed when ethanol and methylphenidate are coingested...and not even that much l-ethylphenidate is formed. So you are not producing an active drug.

Esterase enzymes are responsible for the transesterification, so all mixing methylphenidate and ethanol will yield is a solution of methylphenidate in ethanol.

https://www.ncbi.nlm.nih.gov/pubmed/25303048

https://www.ncbi.nlm.nih.gov/pubmed/21402502

https://www.ncbi.nlm.nih.gov/pubmed/21240977
 
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Based on the first link roughly 4 or 5 shot of alcohol withn a hour of taking methylphenidate may increase the peak conc. By like 33 % and make a insigficient ie less than 10% d ethylphenidate
 
serotonin2A said:
Esterase enzymes are responsible for the transesterification, so all mixing methylphenidate and ethanol will yield is a solution of methylphenidate in ethanol.
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Since the ethanol is in great excess, it will eventually drive almost all the methylphenidate to transesterify. This will take a very long time though, and acid catalysis will greatly speed up the process.
 
aced126 said:
Since the ethanol is in great excess, it will eventually drive almost all the methylphenidate to transesterify. This will take a very long time though, and acid catalysis will greatly speed up the process.
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I don't think this would work under the conditions that the person asked about. There are certainly ways to convert methylphenidate to ethylphenidate, but he specifically asked about mixing methylphenidate with ethanol in a shot glass.
 
I doubt transesterfication woud ever occur with significant yield without the alcohol be it isopropyl or ethyl alcohol is heated at 70 to 100 degrees celcius in the precense of a acid or base catalyst in 0.1 to 1 mimimum up to 5 mol eq. E.x. naoac or potassium phosphate ect. And at these tempertures the alcohol would be in a gas state so its unlikely to ever occur outside of a lab amd the only time it wojld occur at room temperature would be with excess ie 5 mol of emtremely rare expensive catalysts youd never find jjst arpund like carbenes
 
I doubt transesterfication woud ever occur with significant yield without the alcohol be it isopropyl or ethyl alcohol is heated at 70 to 100 degrees celcius in the precense of a acid or base catalyst in 0.1 to 1 mimimum up to 5 mol eq. E.x. naoac or potassium phosphate ect. And at these tempertures the alcohol would be in a gas state so its unlikely to ever occur outside of a lab amd the only time it wojld occur at room temperature would be with excess ie 5 mol of emtremely rare expensive catalysts youd never find jjst arpund like carbenes
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Am I glad he's frozen in there and that we're out here, and that he's the sheriff, and that we're frozen out here, and that we're in there and I just remembered we're out here. What I wanna know is where's the caveman?

Seriously though, transesterification of -phenidates is dumb simple, the reaction does occur at r.t. but slowly. It's a textbook equilibrium reaction. There's lots of literature on it because of the utility of the reaction to make biodiesel, among other things. If you use a large excess of e.g. ethyl alcohol and add your methylphenidate then Le Chatelier's principle says you'll end up with ethylphenidate eventually. Acid or base catalysis will just speed it up - I would imagine that the HCl paired with the methylphenidate would suffice as a catalytic acid due to the fact that an aqueous solution is slightly acidic.

However drinking alcohol isn't anywhere close to pure ethanol - at best you're going to have something that is 40% ethanol and the remainder water. And my gut sense tells me that if you try a transesterification with that much water hanging around , all you'll end up with is ritalinic acid and alcohols.
 
Sorry for the off-topic question but if you were to attempt this with Salvinorin A and ethyl alcohol, would there be both transesterification on the methyl ester as well as deacetylation? If so, do you expect a difference in the rate of transesterifications?

(Assuming that yes you do an acid or base catalyzed reaction properly - which by the way I don't know if salvinorin is destabilized by - edit: apparently can cause C-8 epimerization)

Hmm on a similar fragment of that molecule, going from ethyl ester to methyl ester directly gives no product with refluxing in alcohol. http://scholarscompass.vcu.edu/cgi/viewcontent.cgi?article=2861&context=etd
Is going the other way from methyl to ethyl more feasible? I guess they made the mistake of just doing base hydrolysis instead of acid catalyzed alcohol transesterification? How dry does that have to be though I wonder.
 
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Are you refering to ethyl ester + naoh to carboxylate and esterfication with methanol and sulphuric acid? I believe it doesnt. Matter if your going from ethyl ester to methyl ester the first step of a transesterfication is the hydrolysis of the alcohol carboxylate ester. The important thing here is your paper further shows transesterfication will not occur under normal conditions and inorder to occur it requires catalysts and time and alot of skill in chemistry for any yield
 
(Sorry if this violated the rules for synth discussion im just trying to make clear how such a reaction is very hard to do and would require use if chemicals that would put you at serious risk without proper safety equipment and even if u did make it use without impurities)
 
The catalyst is there, only problem is you apparently need to remove all water present and produced. Since dean stark trap won't work I'd guess ethanol absolute and molsieves in a heaterdried cacl2 dryer fitted refluxer?

Yeah not too sure about transesterification, it's synthy but still a simple conversion reaction that can happen spontaneously with alcohol present - sekio had a gut feeling about the water present and right now that seems to be the recurring culprit.
 
Im not sure about it being spontaneous in fhe paper you linked I believe it was 19 hours under reflux. For poor yield
 
d1nach said:
Im not sure about it being spontaneous in fhe paper you linked I believe it was 19 hours under reflux. For poor yield
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Well "spontaneously" by esterases I meant, not really spontaneous but under normal (physiological) conditions..
 
At the risk of sounding like an idiot....,(which I AM.) Can someone describe somewhat in-depth, the "feel" (stimulation, mood alteration, or the warm fuzzy feel) of the phenidates, and how that it differs from the "feel" produced by m-amphs and amphs.. Oh!!!!. SORRY in advance Mods... I tried to be a good lil' boy..
 
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