An effective synthesis of polynuclear tetraamines, monomers for polyheteroarylenes

An effective synthesis of polynuclear tetraamines via nucleophilic substitution of chlorine in 2-chloro-5-nitroaniline under ultrasonic irradiation followed by catalytic hydrogenation of dinitrodiaminoarenes in a flow reactor was proposed. A number of monomers, including those not described in the literature, were thus obtained. Two classes of polyheteroarylenes, namely, polynaphthoylenebenzimidazoles and polyphenylquinoxalines were synthesized by the polycyclocondensation in a supercritical carbon dioxide. Incorporation of trifluoromethyl substituents and flexible oxygen bridges into the structure of monomers allowed one to improve the solubility of the polymers. Some properties of synthesized polyheteroarylenes were investigated.