[{"from": "human", "value": "Please provide possible reagents based on the following chemical reaction. [Br][Br].[O][=C][C][=C][C][=C][Branch1][C][O][C][=C][Ring1][#Branch1]>>[O][=C][C][=C][C][=C][Branch1][C][O][C][Branch1][C][Br][=C][Ring1][Branch2]"}, {"from": "gpt", "value": "[Cl][C][Branch1][C][Cl][Cl].[O]"}]