Identify the most basic nitrogen atom among the labeled nitrogen atoms in the given structure of LSD.

Step-by-step solution

The basicity of a nitrogen atom depends on the availability of its lone pair of electrons for protonation. For Nitrogen (1), the lone pair is involved in the aromaticity of the indole ring system, making it highly delocalized and least basic. For Nitrogen (3), the lone pair is in resonance with the adjacent carbonyl group of the amide, reducing its availability for protonation. For Nitrogen (2), it is a tertiary aliphatic amine. Its lone pair is localized and not involved in resonance, making it readily available f