[{"from": "human", "value": "Please give me some details about this molecule. [C][C][C][=Branch1][C][=O][N][Branch2][Ring1][Ring2][C][C][C][N][Branch1][Branch1][C][C][Ring1][=Branch1][C][C][C][=C][C][=C][S][Ring1][Branch1][C][=C][C][=C][C][=C][Ring1][=Branch1]"}, {"from": "gpt", "value": "The molecule is a fentanyl analog analgesic that was sold on the black market in the 1980s until the Federal Analog Act scheduled drugs based on structural similarity rather than scheduling drugs individually. Thienylfentanyl has a similar synthesis pathway to fentanyl except 2-(2-bromoethyl)thiophene is substituted for phenethyl bromide."}]