Synthesis of Diphthalonitriles Based on 3,3′,5,5′-Tetrasubstituted Derivatives of 2,2′- and 4,4′-Biphenyldiols

A simple procedure for obtaining previously unknown diphthalonitriles based on 4-nitrophthalonitrile and 3,3′,5,5′-tetrasubstituted biphenyl-4,4′-diol derivatives in a binary solvent system DMF–water was developed. The possibilities and limitations of using 3,3′,5,5′-tetrasubstituted biphenyl-2,2′-diol derivatives as reagents for the synthesis of diphthalonitriles and corresponding dianhydrides were demonstrated. The effect of the substrate nature on the yield of target diphthalonitriles was considered using 2,2′,3,3′,5,5′-hexamethylbiphenyl-4,4′-diol as an example.