You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[5-chloro-6-ethyl-2-[(1-methyl-3H-isoindol-5-yl)sulfanyl]-7H-pyrrolo[2,3-d]pyrimidin-4-yl]cyclobutan-1-amine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H22ClN5S
assistant