[{"from": "human", "value": "Please propose potential reagents that might have been utilized in the provided chemical reaction. [Br][Br].[C][O][C][=C][C][=C][C][=C][Branch1][Ring1][C][#N][C][=C][C][Ring1][Branch2][=C][Ring1][N]>>[C][O][C][=C][C][=C][C][=C][Branch1][Ring1][C][#N][C][=C][C][Ring1][Branch2][=C][Ring1][N][Br]"}, {"from": "gpt", "value": "[C][C][=Branch1][C][=O][O]"}]