['O=CCCl', 'NC(=O)CNc1ccc2c(c1)OCO2', 'CC(N)=O', 'O=C(CCl)Nc1ccc2c(c1)OCO2', 'NC(=O)CNC(=O)CCl', 'c1ccc2c(c1)OCO2']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc2c(c1)OCO2.