You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule 4-[3-(furan-2-yl)-1,2,4-oxadiazol-5-yl]-1-[4-(4-methoxyphenyl)piperazin-1-yl]butan-1-one .
user
C21H24N4O4
assistant