Polyetherimides. I. Preparation of dianhydrides containing aromatic ether groups

A general synthetic method and characterization of bis(ether anhydride)s, the ether containing aromatic dianhydrides of the following structure, are presented. magnified image The method involves aromatic nitro‐displacement of N‐substituted 3‐ or 4‐nitrophthalimide with bisphenoxides to form N‐substituted arylene‐bis(phthalimido)ethers or bis(ether imide)s. Sixteen structurally different bis(ether imide)s have been prepared and subsequently converted to the corresponding bis(ether anhydride)s. Bis(ether anhydride)s are stable crystalline compounds of a moderate reactivity. Unlike highly reactive dianydrides such as pyromellitic and benzophenonetetracarboxylic dianhydrides bis(ether anhydride)s are semipermanently stable against hydrolysis in the presence of atmospheric moisture.