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 1-[4-[4-[3-(5-chlorothiophen-2-yl)-3-oxopropyl]triazol-1-yl]phenyl]-4-methylpyridin-2-one .
user
C21H17ClN4O2S
assistant