The kinetics and mechanisms of aromatic halogen substitution. Part 35. The directive effect of the benzoyloxy-substituent

Abstract

The rates of chlorination of 4-acetamidophenyl benzoate, 1,3-bisbenzoyloxybenzene, and appropriate reference compounds by molecular chlorine in acetic acid at 25 °C have been determined. By using the additivity principle, partial rate factors for chlorination directed by the benzoyloxy-group have thence been calculated, viz. f_v-O·CO·Ph 5.5, f_m-OCO·Ph 0.059, f_p-O·CO·Ph 52. Comparison with analogous results obtained for the acetoxy-group allow estimates to be made of σ⁺ values for the benzoyloxy-substituent. These values are used to discuss the course of halogenation of 2-benzoyloxynaphthalene.