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 (2S)-2-(4-cyanophenoxy)-N-[(2S)-5-ethoxy-2-methyl-2,3-dihydro-1-benzofuran-6-yl]propanamide .
user
C21H22N2O4
assistant