You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 2-[(2R)-4-[(3-chloro-4,5-dimethoxyphenyl)methyl]-1-(3-methylbutyl)piperazin-2-yl]ethanol into molecular formula.
user
C20H33ClN2O3
assistant