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 3-[6-[(2-chlorophenyl)methylamino]-[1,2,4]triazolo[4,3-b]pyridazin-3-yl]-N-pyridin-2-ylpropanamide .
user
C20H18ClN7O
assistant