You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule 7-chloro-2-[1-[4-(4-chloro-3-nitrobenzoyl)piperazin-1-yl]ethyl]-3-methylquinazolin-4-one ?
user
C22H21Cl2N5O4
assistant