Question

How can I name compounds with multiple functional groups?

Answer 1

IUPAC, an international commission, has layed out the rules for this.

Explanation:

The idea is that the same compound cannot, or must not, have two (or more) different names. If there are more functional groups, e.g. a `-OH` and a `-COOH` as in lactic acid, the naming is defined as 2-hydroxypropanoic acid, because the acid part has preference as a suffix. If this preference didn't exist, other names would be possible (work that out for yourself).

The rules:
https://en.wikipedia.org/wiki/IUPAC_nomenclature_of_organic_chemistry