When naming substituted benzenes:
- 1. Identify the parent chain, which is the benzene containing the highest-priority functional group. That parent chain is the parent chain name.
- 2. The carbon atom in the ring that is attached to the priority functional group is numbered as carbon #1.
- 3. Number around the ring in whichever direction (clockwise or counterclockwise) that gives the lowest number at the first point of difference.
- 4. If the numbers are the same in both directions, pick the one that gives the lower number to the substituent that is alphabetically first.