You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[4-[(5,7-dimethylimidazo[1,2-a]pyrimidin-2-yl)methyl]piperazin-1-yl]sulfonylbenzonitrile The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H22N6O2S
assistant