tryptophan decarboxylation

yaya · Thu May 19, 2005 6:17 am

Need some help with some basic chemistry/technique regarding tryptophan decarb. Lots of help.

Decarb via reflux in cyclohexanol with enone catalyst (under nitrogen). Reaction monitored by co2 evolution. When co2 evolution stops reaction will be stopped. co2 collected and volume measured to give some preliminary idea of yield.

Seems like cyclohexanol is soluble (to too much extent) in every thing and visa versa. So a typical AB extraction seems (?) out of the question (no polar/non polar) Seems dry HCl gas is the way to go. Lets assume some success, after dry gas, now have a mixture of tryptamine-HCl and tryptophan-HCl. So filter and purify.

From MERK we find that for trptamine-HCl, recryst from ethoh/ethyl acetate….and
That for typtophan-HCl, recryst from methanol.

Did not see boiling point/vapor pressure for each compound in MERK, theoretically have access to direct drive two stage vac pump…..ie…. if good vacuum could be had would this be a preferred method of separation? Distillation/sublimation?

OK ramble babble,,,,to the point;

Would love to think this could go with out having to resort to HCl gas. Any options? Concerns are recycling cyclohexanol easily. If must resort to gas, how to purify cyclohexanol again? Simple distill? Bring the ph to normal cyclohexanol ph and then distill? Is the solvent system for recryst of the two compounds different enough for clean separation?

What I am ultimately after is a smooth clean separation, with clean tryptamine base and clean cyclohexanol solvent (its ok if some catalyst is left) in the end. HCL gas and vacuum technique would love to be avoided, but what ever is reality is reality.

I hope my line of questioning gives an idea of my lack of knowledge. Any light shed on my assumptions is welcome….it’s dim in here.

I welcome and very much appreciate any thought’s about this decarb system (cyclohexanol, enone) that will lead to clean tryptamine base and clean solvent that is ready to go again, be it simple or involved.
Heck, any thought’s bout tryp decarb would be nice,

Thanks very much for your time, expertise and musings.

brain · Linguist Extraordinaire

HCl gassing.... mabeby make tryptamine-sulphate? [H2SO4 98%+IPA] it should work to ?

I want to puryfy fproduct on preparatic TLC , for schowin indoles i want to use DAB 1% solution, i have then make 2 different TCL's to compare result, on first i will add pure tryptophan on second pure tryptamine, and than compare it with preparatic TLC - then get pure tryptamine phase, and extract