Using O=C1OC(=O)c2c(F)c(F)c(F)c(F)c21, CN1C(=O)NC(=O)C(C)(N)C1=O to produce CN1C(=O)NC(=O)C(C)(N2C(=O)c3c(F)c(F)c(F)c(F)c3C2=O)C1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.