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