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-[(E)-4-chloro-2-methylbut-2-enoyl]-7-fluoro-5-propan-2-yl-2,3-dihydro-1H-pyrrolo[1,2-a]indol-3-yl]acetic acid .
user
C21H23ClFNO3
assistant