Charge-transfer Interaction and Chemical Reaction. V. Reaction of o-Phenylenediamine with Chloranil

Abstract

Abstract The reaction of o-phenylenediamine with chloranil in ether was studied by measuring visible and ultraviolet absorption spectra at various temperatures between −78 °C and room temperature. Dehydrogenation of o-phenylenediamine by chloranil occurred, o,o′-diaminoazobenzene, 2,3-diaminophenazine and tetrachlorohydroquinone being produced as main reaction products. It was suggested that the reaction involves o-benzoquinone di-imine as an intermediate. For the sake of confirmation, o-benzoquinone di-imine was prepared by an independent method, and its reaction with o-phenylenediamine was examined. The difference in reactivity of isomeric phenylenediamines toward chloranil is discussed.