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 5-ethyl-7-(2-methylpiperidin-1-yl)-2-phenyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one .
user
C19H23N5O
assistant