Basicity of Arylamines Electron-donating substituents which ABLE12 Base Strength of Some p-Substituted Anilines increase the reactivity NH2 H20 NH3 +OH for an aromatic ring Substituent,Y pKa toward electrophilic Stronger -NH2 6.15 substitution also base increase the basicity of -OCH3 5.34 Activating groups the aryl amine _CH3 5.08 Electron-withdrawing substituents which -H 4.63 decrease ring reactivity 3.98 toward electrophilic substitution also -Br 3.86 Deactivating groups decrease arylamine -CN 1.74 basicity Weaker base -NO2 1.00 Electron-donating substituents which increase the reactivity for an aromatic ring toward electrophilic substitution also increase the basicity of the aryl amine Electron-withdrawing substituents which decrease ring reactivity toward electrophilic substitution also decrease arylamine basicity Basicity of Arylamines