Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Nescafe on February 10, 2015, 05:44:31 PM
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Hi,
Might be a bad question but I was wondering, if the starting material is a HCl salt that I plan to use, and in the reaction flask I have a strong base like Cesium carbonate or even NaH, would I still need to add TEA to remove the HCl?
Let us say I have a stirring solution of a strong base in THF and my reactant that the NH2 . HCl is going to react with, do I need to premix the NH2 HCl in a bit of solvent and base or can I just add it in knowing that NaH that is stirring in solution will take care of the HCl itself?
Not sure if I am making any sense,
Thanks in advance,
Nescafe.
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May I ask what reaction you are intending to do.
To answer your question, if you shovel your amino acid HCl salt into a suspension/solution of NaH you will get the free amine.
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Thanks for the response. I was just wondering since I saw someone do it and I was wondering why they added base. Cause I thought as you said NaH would be sufficient to liberate the Amine.
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Just to clarify, as I understand this question, no change in the equilibrium will occur, but a catalyst may change the kinetics of the reaction. The problem is the low solubility of the reagents in a given solvent. If water or alcohol were used, the solubility and reactivity would change and the reaction would occur, though with an intermediate reaction of an ROH with NaH.
If one were trying to react the hydrochloride salt with NaH in a solvent like toluene, the low solubility would make this reaction very slow or no reaction at all. If a catalytic amount of t-butanol were added, it could react more quickly with the NaH as it is soluble in toluene. The NaOtBu could react more quickly with the amine-HCl if its solubility were similar to KOtBu, and regenerate t-butanol.