You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
tert-butyl (3R)-4-[6-(2,2-dimethylpropyl)pyrimidin-4-yl]-3-methylpiperazine-1-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H32N4O2
assistant