You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 5-methyl-2-[(3R)-1-(1-methylsulfonylpiperidine-4-carbonyl)piperidin-3-yl]-1H-pyrazolo[1,5-a]pyrimidin-7-one .
user
C19H27N5O4S
assistant