You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule ethyl 2-[[2-(1-benzofuran-2-yl)-2-oxoethyl]amino]-5,6-dihydro-4H-cyclopenta[b]thiophene-3-carboxylate ?
user
C20H19NO4S
assistant