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 2-(4-fluorophenyl)-1-[3-[[6-(5-methyl-1H-imidazol-2-yl)pyrimidin-4-yl]methyl]pyrrolidin-1-yl]ethanone .
user
C21H22FN5O
assistant