Using COCCl, CCOC(=O)c1cc2c(Cl)c(O)cc3c2n1CCCCC3=O to produce CCOC(=O)c1cc2c(Cl)c(OCOC)cc3c2n1CCCCC3=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.