[{"from": "human", "value": "From the provided chemical reaction, propose some possible reagents that could have been used. [C][C][=C][C][=C][Branch1][C][Br][C][=N][Ring1][#Branch1].[O][O]>>[C][C][=C][C][=C][Branch1][C][Br][C][=N+1][Ring1][#Branch1][O-1]"}, {"from": "gpt", "value": "[C][C][=Branch1][C][=O][O].[Cl][C][Cl].[O][=C][Branch1][C][O-1][O-1].[K+1].[K+1]"}]