You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule ethyl 6-methyl-4-[2-[(4-methylphenyl)methylamino]-2-oxoethyl]sulfanyl-2-oxo-1H-pyrimidine-5-carboxylate ?
user
C18H21N3O4S
assistant