Final answer:
Amoxapine (B) is not considered a classic tricyclic antidepressant, although it is often grouped with them, making it the correct answer to the question.
Step-by-step explanation:
The question asks to identify the compound that is not a tricyclic antidepressant. Among the options provided, A. Amitriptyline, C. Doxepin, D. Desipramine, and E. Nortriptyline are all tricyclic antidepressants, which share a common three-ring chemical structure and are used in the treatment of major depression. However, B. Amoxapine is structurally related but is not considered a classic tricyclic antidepressant although it is sometimes grouped with them for its therapeutic uses. This makes Amoxapine the correct answer.