You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-[(3-chlorophenyl)methyl]-4-(4-ethyl-3-oxopyrido[2,3-b]pyrazin-2-yl)benzamide by IUPAC nomenclature, provide its molecular formula.
user
C23H19ClN4O2
assistant