Ai
Suvey said
"
You hit the nail on the head.
Your chemistry logic is entirely correct, and your analogy to esters and alcohols is perfect.
The reason this forum "recipe" fails in a kitchen comes down exactly to the fundamental difference between an
amide and an
amine—specifically, how their nitrogen atoms behave due to
resonance.
Here is why your observation perfectly explains why the reaction doesn't work the way forum posters think it does:
1. The Amide vs. Amine Difference (The Resonance Trap)
In a normal
amine, the nitrogen atom has a localized lone pair of electrons. This makes it highly nucleophilic and ready to attack an aldehyde to form an imine (Schiff base) relatively easily.
However, Ergine (LSA) does not have a simple amine there; it has a primary
amide (\(\text{-CONH}_{2}\)).
- Because it is attached to a carbonyl group (\(\text{C=O}\)), the lone pair of electrons on the amide nitrogen is not sitting locally on the nitrogen.
- Instead, those electrons are delocalized into the carbonyl group via resonance.
- This drastically reduces the nucleophilicity of the nitrogen. It is a terrible nucleophile compared to a regular amine.
2. Your Ester vs. Alcohol Analogy is Spot On
Your comparison is chemically identical to what is happening here:
- An alcohol (\(\text{R-OH}\)) has an oxygen with available lone pairs.
- An ester (\(\text{R-COO-R}^{\prime }\)) has its oxygen lone pairs tied up in resonance with its carbonyl group.
Just like you can't easily get an ester oxygen to act with the same nucleophilic reactivity as an alcohol oxygen, you cannot get an amide nitrogen to react smoothly with an aldehyde the way an amine would.
What Actually Happens (Why the Myth Fails)
Because of this low reactivity, a primary amide and an aldehyde (like acetaldehyde) will not cleanly "join" just by mixing them together in a glass of wine or peppermint tea at room temperature.
To actually force an aldehyde to attach to an amide nitrogen to form a carbinolamide or a bis-amide, a chemist usually has to introduce
strong acid catalysts, high heat, or specific dehydrating conditions to drive equilibrium forward. In a cold, watery kitchen extraction, the equilibrium heavily favors the reverse reaction—meaning the LSA and acetaldehyde just sit next to each other as separate ingredients, completely unreacted.
The forum posters see the word "nitrogen" and assume it reacts like an amine, completely missing the resonance stabilization of the amide group that you just pointed out.
Are you analyzing this for a
chemistry project/hobby, or are you trying to win an argument with a stubborn
forum user?"