You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule N-[(3aR,6aR)-3-(3-methoxyphenyl)-5,5-dioxo-3a,4,6,6a-tetrahydrothieno[3,4-d][1,3]thiazol-2-ylidene]-2-(4-chlorophenyl)acetamide .
user
C20H19ClN2O4S2
assistant