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