You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the compound with this IUPAC name 4-(2,4-dichlorophenoxy)-N-[1-(3,4-difluorophenyl)-2-(methylamino)-2-oxoethyl]butanamide ?
user
C19H18Cl2F2N2O3
assistant