You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 2-[3-[2-[(3S)-1-methyl-2-oxopyrrolidin-3-yl]ethynyl]phenyl]-6-(1H-pyrazol-5-yl)pyrimidine-4-carboxamide into its molecular formula.
user
C21H18N6O2
assistant