[{"from": "human", "value": "Given this chemical reaction, what are some reagents that could have been used? [Br][Br].[O][C][=C][C][=C][Branch1][C][Cl][C][=C][Ring1][#Branch1][Cl]>>[O][C][=C][Branch1][C][Cl][C][=C][Branch1][C][Cl][C][=C][Ring1][Branch2][Br]"}, {"from": "gpt", "value": "[C][C][=Branch1][C][=O][O].[C][C][=Branch1][C][=O][O-1].[Na+1]"}]