Clayden et al. demonstrated the existence of enol anions by experiments. The proton was extracted by the base to obtain an enol intermediate, then subjected to an aromatic nucleophilic substitution to obtain another anion intermediate. The product is obtained by work up. For the aromatic nucleophilic substitution reaction whose reaction constant is significantly smaller than normal, it is explained that the reaction mechanism will be different from the conventional aromatic nucleophilic substitution reaction mechanism and will not undergo the Meisenheimer complex(Fig. ). However, due to lack of mechanism experiments and detailed calculation data, other intermediates have not been captured. The specific mechanism of this reaction has not yet been elucidated.