Step 1: Understanding the Concept:
Propranolol is the prototype non-selective beta-adrenergic blocker. Its name describes its chemical structure.
Step 2: Detailed Explanation:
1. Structure Components: It contains a naphthyl group (Aryl), an oxygen bridge (Oxy), and a propanolamine side chain (\(-CH_2-CH(OH)-CH_2-NH-\)).
2. Classification: Combining these elements, it is classified as an aryloxypropanolamine. This structural motif is common to most first and second-generation beta-blockers.
Step 3: Final Answer:
Propranolol is structurally defined as an aryloxypropanolamine derivative.