You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
8-bromo-N-[4-(dimethylamino)phenyl]-2-ethyl-6-methylimidazo[1,2-a]pyridine-3-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H21BrN4O
assistant