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 [1-ethyl-5-hydroxy-2-methyl-3-(3-methyl-1,2-oxazol-5-yl)-4-methylsulfonylpyrazolidin-4-yl]-phenylmethanone .
user
C18H23N3O5S
assistant