You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named N-[4-chloro-2-[(2R,6R)-2,6-dimethylpiperidine-1-carbonyl]phenyl]-2-[(1R)-cyclopent-2-en-1-yl]acetamide is given. What is its corresponding molecular formula?
user
C21H27ClN2O2
assistant