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-(butylcarbamoyl)-2-[(4S)-4-thiophen-2-yl-6,7-dihydro-4H-thieno[3,2-c]pyridin-5-yl]acetamide .
user
C18H23N3O2S2
assistant