You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named propyl (4S,7R)-7-(4-methoxyphenyl)-2-methyl-4-(4-nitrophenyl)-5-oxo-4,6,7,8-tetrahydro-1H-quinoline-3-carboxylate by IUPAC nomenclature, provide its molecular formula.
user
C27H28N2O6
assistant