You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule 4-(5,6-dimethyl-[1,2,4]triazolo[1,5-a]pyrimidin-7-yl)-1-[(3-methylphenyl)methyl]piperazin-2-one ?
user
C19H22N6O
assistant