When the two substitutions are different in arenes, they are put in which of the following order?

Explanation

The substituents in arenes are put in alphabetical order when they are different. The substituents are listed in alphabetical order, regardless of their numerical value. For example, the compound 1-chloro-2-methylbenzene would be named as such, not 2-chloro-1-methylbenzene. The substituents are also listed in alphabetical order regardless of their size. For example, the compound 1-bromo-3-ethylbenzene would be named as such, not 3-bromo-1-ethylbenzene. The only exception to this rule is when the substituents are the same. In this case, the substituents are listed in numerical order. For example, the compound 1,2-dichlorobenzene would be named as such, not 1,1-dichlorobenzene.