You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[5-(2-chlorophenyl)-4-oxo-3H-thieno[2,3-d]pyrimidin-2-yl]methyl 2-[(1R,2R,4S)-2-bicyclo[2.2.1]heptanyl]acetate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H21ClN2O3S
assistant