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 8-(4-chlorophenyl)-N-[(4-chlorophenyl)methyl]-1-oxa-2,8-diazaspiro[4.5]dec-2-ene-3-carboxamide .
user
C21H21Cl2N3O2
assistant