Chapter 23, Problem 39PP

 (a)

Interpretation Introduction

Interpretation: For the given compound, clomipramine, the more basic nitrogen atom and the form that predominates at physiological pH have to be found

Concept Introduction:

If the lone pair of electrons on nitrogen atom in amine compound is delocalized, that compound is resonance stabilized.  It is also involved in aromatic stabilization.  As a result, a number of resonance structures are drawn for the delocalization of electrons in the structures.  So, the compound has less basic character.  If the lone pair of electrons on nitrogen atom in amine compound is localized, that compound doesn’t involve in resonance stabilization.  So, that compound has more basic character.

To find: Get the more basic nitrogen atom in clomipramine

Get nitrogen where lone pair is delocalized

(b)

Interpretation Introduction

Interpretation: For the given compound, clomipramine, the more basic nitrogen atom and the form that predominates at physiological pH have to be found

Concept Introduction:

The amine groups are allowed to exist as positively charged ammonium ion at physiological pH.  This ammonium ion predominates at physiological pH.

To find: Draw the form that predominates at physiological pH for clomipramine

Find the nature of nitrogen atoms in clomipramine