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 2-[(1-cyclopropylbenzimidazol-2-yl)methylamino]-7-ethyl-[1,3,4]thiadiazolo[3,2-a]pyrimidin-5-one ?
user
C18H18N6OS
assistant