[{"from": "human", "value": "Given this chemical reaction, what are some reagents that could have been used? [Br][C][C][=N][NH1][C][=Ring1][Branch1].[Cl][C][C][Br]>>[Cl][C][C][N][C][=C][Branch1][C][Br][C][=N][Ring1][=Branch1]"}, {"from": "gpt", "value": "[C][N][Branch1][C][C][C][=O].[O][=C][Branch1][C][O-1][O-1].[Cs+1].[Cs+1]"}]