Synthesis of Bisaniline A and Derivatives with Perfluorinated Sulfonic Acid Resins

Abstract

Bisaniline A (BAA) and its derivatives are diamine monomers with ignificant potential applications in polyimides, polyamides, and as a component in epoxy systems. BAA may be prepared by any of three acid-mediated routes: reaction of aniline with acetone; alkylation of aniline with p-isopropenylaniline; or transarylation of a ring-alkylated bisphenol A with aniline. Further, transarylation of ring-alkylated bisphenols is difficult to drive to completion, since aniline is generally the lowest boiling component of the mixture. Alkylation of aniline with isopropenylaniline is the most selective, highest yield route to BAA. BAA and unsymmetrically substituted BAA derivatives are readily prepared by alkylation of aniline or a substituted aniline with p-isopropenylaniline in the presence of a perfluorinated ion exchange resin. Bulk resins such as Nafion® or supported acidic cation exchange resins such as XU-40036® perfluorinated ion exchange polymers coated on inorganic supports; available from Dow as developmental products can be used.