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Separation of harmane and harmine?

Migrated topic.

Elrik

Rising Star
Its almost time to extract more harmalas and I'm curious if any practical method has been devised for removal of harmane from harmine?
By practical I mean not flash chromatography or vacuum sublimation šŸ˜‰
They seem to have nearly identical pKa's, from the literature it seems harmaneā€¢HCl will 'manske' out with excess chloride ions the way harmineā€¢HCl does, I'm not seeing any clear indication of harmanes solubility in toluene but it will crystallize from hot heptane. Its listed as soluble to the extent of 50 mg/ml in methanol, that might be a clue.
I'd like to try harmane-free harmine, but my only viable Ɵ-carboline source is P. harmala.
 
Preparative TLC might be an option.

After running a small sample to see whether there's any significant amount of harmane present and find out the Rf of harmine versus harmane under those conditions. Obviously your choice of mobile phase will have to be determined carefully. The experiment then can be repeated with a whopping great sheet of blotting paper, er, much larger width of stationary (stationery šŸ˜ ) phase and the appropriate band, as per the determined Rf, cut out and re-extracted.

How's that sound? I don't think it's very practical for large-scale work, but it might suffice on a per-dose basis.
 
Thats good to hear about your analyses. :)

I inferred the manske thing from an entry in the merck index, eighth edition:
Harman Hydrochloride... rosettes of needles from ethanol + 20% HCl in water
It sounds like they were using HCl to reduce solubility and help it crystallize out just as happens with harmineā€¢HCl and HCl [or NaCl].
 
Harman Hydrochloride... rosettes of needles from ethanol + 20% HCl in water
It sounds like they were using HCl to reduce solubility and help it crystallize out just as happens with harmineā€¢HCl and HCl [or NaCl].
Sounds to me more like they were utilising the difference solubility of harmane freebase and harmane HCl in ethanol, maybe bolstered by the common-ion effect from any extra HCL. Probably cooling of the hot ethanol was used as well.
 
I considered that possibility, thats why I said I inferred it.
However, when a chemical reference book is talking about crystallization they are almost invariably talking about solvent effects on an unaltered compound, not the synthesis of a new compound. They know this is what people expect so if they deviate from that they generally say so.
Put harmineā€¢HCl in water and dump in a mix of ethanol and 20% HCl and you'll get crystals, no doubt. Harmane is chemically very close to harmine so the mercks protocol didnt surprise me.
 
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