Production of dioxazine compound.

摘要

Dioxazine compounds of the formula (I) which are useful for dyes or pigments are prepared by heating a compound of formula (II)
<Chemistry id="chema01" num="0001"><Image id="ia01" he="36" wi="176" file="IMGA0001.TIF" imgContent="chem" imgFormat="TIFF" /></Chemistry> in the presence of inorganic acid with or without an oxidizing agent in an inert organic solvent: wherein R is a C<Sub>1-4</Sub> alkyl group, and each of X₁ and X₂ is a hydrogen atom or a chlorine atom.