THE FIRST BRANCHED BENZOXAZINOPHENOTHIAZINE RING SYSTEM AND ITS AZA-ANALOGUES

Article abstract of DOI:10.1016/S0040-4020(01)85898-1

The synthesis of a branched benzoxazinophenotiazine heterocycle is described.The parent compound benzo<1,4>-benzoxazino<3,2-c>phenothiazine (12), was obtained from 2,3-dichloro-1,4-naphthoquinone (6), 2-aminophenol and 2-aminothiophenol.Monoaza-, diaza- and triaza- analogues of this novel heterocycle were also synthesized.The parent compounds, 16-oxa-15-thia-4,5,10,14-tetraazabenzopentaphene (18) and 16-oxa-15-thia-4,5,10,14-tetraazabenzopentaphene (22, R=H) were also synthesized as well as 4-amino-16-oxa-15-thia-4,5,10,14-tetraazabenzopentaphene (24).They are intensely coloured high-melting solids suitable for application as pigments.Their ease of reduction with Na2S2O4 and the ready oxidation of the reduced compounds to applicability also as vat dyes.