Localized stress-affected chemical reactions between solid and diffusive reactants are studied based on the chemical affinity tensor approach. A kinetic equation for the chemical reaction front, such that the interface velocity depends on the normal component of the chemical affinity tensor, is formulated and used for solving coupled boundary value problems of mechanochemistry. It is shown that mechanical stresses can retard and block the reaction front propagation, and the blocked reaction front can be stable or unstable. Considering a plane chemical interface problem, a stability check based on combination of PTZ approach and numerical simulation is done. Then, for a configuration with a stable position of the blocked reaction front the kinetics of the interface is analyzed in the presence of a void or solid inclusion.