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