You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[3-[[5-chloro-2-[[1-(2-hydroxypropyl)pyrazol-4-yl]amino]-7H-pyrrolo[2,3-d]pyrimidin-4-yl]oxymethyl]-4-methoxypyrrolidin-1-yl]prop-2-en-1-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H26ClN7O4
assistant