Synthesis and the Structure of Carbazole Dioxazines

Abstract

Synthesis and the structure of the carbazole dioxazine pigment were investigated. The carbazole dioxazine with a linear structure, 5, 15-diethyl-8, 18-dichloro-5, 15-dihydrodiindolo[3, 2-b: 3', 2'-m]triphenodioxazine [I], was newly synthesized by demethanolation of 2, 5-bis(9-ethyl-2-methoxy-3-carbazolylamino)-3, 6-dichloro-1, 4-benzoquinone [9] in 1-chloronaphthalene. Compound [I] is green powder showing the absorption maxima at 540 and 584 nm. Qn the other hand, the ring closure of [9] with p-toluenesulfonyl chloride in DMSO afforded 5, 15-diethyl-9, 19-dichloro-7, 17-dimethoxy-5, 15-dihydrodiindolo [3, 2-a: 3', 2'-1]triphenodioxazine [III] having an angular structure. It was concluded that [X] has not a linear structure by comparing the properties of [I] with those of carbazole dioxazine (X) conventionally obtained. Carbazole dioxazine, 5, 15-diethyl-5, 15-dihydrodiindolo[3, 2-b: 3', 2'-m]triphenodioxazine [IV] (linear structure) and 5, 15-diethyl-7, 17-dimethoxy-5, 15-dihydrodiinolo[3, 2-a: 3', 2'-1]triphenodioxazine [V] (angular structure)not containing chlorine atoms were synthesized and the effect of chlorine atom was examined.