[{"from": "human", "value": "Please suggest some possible reagents that could have been used in the following chemical reaction. [C][O][C][=C][C][=C][C][=C][Branch1][C][N][C][=C][C][Ring1][#Branch1][=C][Ring1][O].[O][=C][C][C][C][=Branch1][C][=O][N][Ring1][=Branch1][Br]>>[C][O][C][=C][C][=C][C][Branch1][C][Br][=C][Branch1][C][N][C][=C][C][Ring1][Branch2][=C][Ring1][N]"}, {"from": "gpt", "value": "[C][C][#N]"}]