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 2-[2-(7-bicyclo[4.2.0]octa-1,3,5-trienyl)-2-oxoethyl]-4-(4-chlorophenyl)thiophene-3-carboxylic acid ?
user
C21H15ClO3S
assistant