Rule 1. In monosubstituted benzenes, the substituent is named first, followed by the word benzene.
Rule 2. In disubstituted benzenes, the positions of the substituents are indicated using the prefixes ortho- (o-), meta- (m-) and para- (p-). The locators 1,2-, 1,3- and 1,4- can also be used.
Rule 3. In benzenes with more than two substituents, the ring is numbered in a way that the substituents receive the lowest locators. If multiple numbering possibilities give the same locators, alphabetical order is preferred.
Rule 4. There are numerous benzene derivatives with common names that are useful to know: