You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule N-(4-methylphenyl)-2-(5-oxo-3-phenyl-6,7-dihydro-4H-pyrazolo[1,5-a]pyrimidin-6-yl)acetamide .
user
C21H20N4O2
assistant