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 2-[2-[4-(3-chloropyridin-4-yl)piperazin-1-yl]ethyl]-7,8-dihydro-5H-thiopyrano[4,3-c]pyridazin-3-one ?
user
C18H22ClN5OS
assistant