You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
6-[2-[(3R)-3-benzylpiperidin-1-yl]-1-hydroxyethyl]-5-chloro-3H-1,3-benzoxazol-2-one;hydrochloride is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H24Cl2N2O3
assistant