You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule 2-(3-chlorophenoxy)-1-[(2R)-2-(6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]azepin-3-yl)pyrrolidin-1-yl]ethanone ?
user
C19H23ClN4O2
assistant