A versatile approach for the functionalization of a bisphenolic monomer, 3,8-bis(4-hydroxyphenyl)-N-phenyl-1,2-naphthalimide (1) as well as its corresponding poly(N-phenyl imido aryl ether sulphone) via transimidization reactions with hydrazine monohydrate, aliphatic amines, and an amino acid (11-amino undecanoic acid) is reported. The reactions proceeded in high conversion and high isolated yield to the desired novel functionalized monomers or polymers with N-amino, N-aliphatic, and N-aliphatic acid pendant groups. The N-amino functionalized monomer, 2, was reacted cleanly with naphthalic anhydride to form a bisimide. Polymers with phthalimide (7), 3-carboxy phthalimide (9), and bisphenol-A-(monoimide monoanhydride) (8) pendant groups were also formed by imidization of 6. A polymer with a cyclopropyl amide functional group, 10, was formed by reacting 6 with cyclopropyl carbonyl chloride. A brief description of the transimidization reactions and the properties of the functionalized polymers is included.