You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance N-(3,4-difluorophenyl)-2,2-dimethyl-3-oxo-3-(4-pyridin-2-ylpiperazin-1-yl)propanamide .
user
C20H22F2N4O2
assistant