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 (Z)-2-(morpholine-4-carbonyl)-3-(4-oxo-2-piperidin-1-ylpyrido[1,2-a]pyrimidin-3-yl)prop-2-enenitrile .
user
C21H23N5O3
assistant