You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
butyl 2-[(2-chlorophenyl)methylsulfanyl]-5-methyl-7-(4-propan-2-yloxyphenyl)-4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H31ClN4O3S
assistant