A Simple Synthesis of 4,5-Disubstituted 1,2-Dicyanobenzenes and 2,3,9,10,16,17,23,24-Octasubstituted Phthalocyanines

Abstract

4,5-Dichloro-1,2-dicyanobenzene (5) was prepared in an overall yield of 49% from 4,5-dichloro-1,2-benzenedicarboxylic acid (1). The reactions of 5 with phenols, thiophenol and 1-propanethiol led in a nucleophilic displacement reaction to the 4,5-bis(aryloxy)-,4, 5-bis(phenylthio)-and 4,5-bis(propylthio)-1,2-dicyanobenzenes 6 which were converted in the presence of 1,8-diazabicyclo [5.4.0]undec-7-ene in high yields to octasubstituted phthalocyanines (tetrabenzoporphyrazines) 7. Some compounds 7 contain eight free phenolic, carboxylic acid or pyridyl groups.