You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 1-[2-[[4-[5-chloro-2-(cyclohexylamino)pyrimidin-4-yl]pyridin-2-yl]amino]ethyl]pyrrolidin-2-one .
user
C21H27ClN6O
assistant