I am doing a coupling reaction between aldehyde and amine, while doing amine variation, I came across amine hydrochlorides. I am following one method, results are not satisfactory. The reaction condition which I am following is moisture sensitive.
I think you need to use the same equivalent(s) for both aldehyde and amine
Try doing the reaction in the presence of a carbonate (potassium, sodium, cesium) in something like DMF. This way the deprotonation of the hydrochloride is irreversible and you should be able to filter off the carbonate at reaction conclusion and removed DMF by rotary.
Are you just making imines?
cheers
Luke
Yeah solubility would be a problem, in that case add 1 eq of DBU or DIPEA to the reaction
You can neutralize amine hydrochlorides salt by adding qua. NaOH(1M) to liberate free amine, it may change color if your earlier compd. is colored.Then extract in ether /benzene to remove solvent & get amine?
I've coupled amine hydrochlorides and acid chlorides by adding an excess of triethylamine (~2.5 equiv) in CHCl3 and heating.
I increased the temperature for convenience sake. It should still work at RT, but not as fast. It also depends on how soluble your amine hydrochloride is. Mine had six carbons and two amine hydrochlorides, so it was barely soluble in chloroform. A larger carbon to hydrochloride ratio should help solubility and reduce the need for heat. Also, triethylamine is fairly easy to either purchase dry or dry yourself.
If possible one of your reactant make Na or K salt, thus you get KCl or NaCl we can separate it . no need to add HCl quenchers........
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