[{"from": "human", "value": "From the provided chemical reaction, propose some possible reagents that could have been used. [C][C][O][C][=N][C][=C][Branch1][C][Br][C][=C][Ring1][#Branch1][N+1][=Branch1][C][=O][O-1]>>[C][C][O][C][=N][C][=C][Branch1][C][Br][C][=C][Ring1][#Branch1][N]"}, {"from": "gpt", "value": "[C][C][O][C][Branch1][C][C][=O].[Cl][Sn][Cl].[O][=S][=Branch1][C][=O][Branch1][C][O-1][O-1].[Na+1].[Na+1].[Na+1].[OH1-1]"}]