You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule 2-[4-[3-chloro-5-(trifluoromethyl)pyridin-2-yl]piperazin-1-yl]-N-(4-ethoxyphenyl)propanamide .
user
C21H24ClF3N4O2
assistant