[{"from": "human", "value": "From the provided chemical reaction, propose some possible reagents that could have been used. [Br][Br].[C][C][O][C][=Branch1][C][=O][C][C][=C][C][=C][Branch1][C][O][C][=C][Ring1][#Branch1]>>[C][C][O][C][=Branch1][C][=O][C][C][=C][C][=C][Branch1][C][O][C][Branch1][C][Br][=C][Ring1][Branch2]"}, {"from": "gpt", "value": "[Cl][C][Branch1][C][Cl][Branch1][C][Cl][Cl]"}]