You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[2-[4-(2-chlorophenyl)piperazin-1-yl]-2-oxoethyl]-3,4,5-trimethoxybenzamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H26ClN3O5
assistant