You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N'-(6-chloro-2,5-dimethylpyrimidin-4-yl)-3-methoxy-5-phenylthiophene-2-carbohydrazide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H17ClN4O2S
assistant