[{"from": "human", "value": "Please suggest some possible reagents that could have been used in the following chemical reaction. [C][C][N][C][C][N][Ring1][=Branch1].[O][=N+1][Branch1][C][O-1][C][=C][C][=C][Branch1][C][Br][C][=N][Ring1][#Branch1]>>[O][=N+1][Branch1][C][O-1][C][=C][C][=C][Branch1][=Branch2][N][C][C][N][C][C][Ring1][=Branch1][C][=N][Ring1][N]"}, {"from": "gpt", "value": "[C][C][#N]"}]