Nylon-6 feedstock — Caprolactam, the monomer used to make nylon-6, is industrially produced starting from which primary aromatic feedstock?

Introduction / Context:
Nylon-6 is a major engineering and textile polymer produced by ring-opening polymerization of caprolactam. Understanding the upstream petrochemical pathway is core chemical technology knowledge.

Given Data / Assumptions:

• We are selecting the principal industrial route to caprolactam.
• Modern routes commonly begin with benzene.

Concept / Approach:
Industrial synthesis typically proceeds: benzene → cyclohexane → cyclohexanone (or cyclohexanone oxime) → caprolactam (via Beckmann rearrangement). Alternative routes have existed historically, but benzene-based routes dominate due to availability and economics.

Step-by-Step Solution:
Identify mainstream feed: benzene.Hydrogenate/oxidize sequence → cyclohexanone.Convert to oxime; Beckmann rearrangement → caprolactam.

Verification / Alternative check:
Process economics and global capacity reports confirm benzene-based routes as the principal industrial method.

Why Other Options Are Wrong:

• Phenol and toluene: used in other syntheses; not the dominant caprolactam starting points today.
• Naphthalene, pyridine: not standard modern routes for caprolactam production.

Common Pitfalls:
Confusing nylon-6 (caprolactam) with nylon-6,6 (adipic acid + hexamethylenediamine) feedstocks.

Final Answer:
Benzene (via cyclohexanone/oxime route)