You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the compound with this IUPAC name [4-(imidazo[1,2-a]pyridin-2-ylmethyl)piperazin-1-yl]-(4-methylsulfonylphenyl)methanone ?
user
C20H22N4O3S
assistant