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-[[4-hydroxy-1-(1,6-naphthyridin-4-yl)piperidin-4-yl]methylamino]-3,3-dimethyl-5-oxopentanoic acid .
user
C21H28N4O4
assistant