Improved Preparation of 6,13-Dichlorotriaryldioxazines using (Diacetoxyiodo)benzene

Abstract

6,13-Dichlorotriaryldioxazines (DClTADO) 1 have been synthesized from 2,5-bis(arylamino)-3,6-dichloro-1,4benzoquinones (BADClBQ) 2 by oxidation with (diacetoxyiodo)benzene (DIB) under mild conditions in good yields.

Azine Dyes

“…Several modifications of the cyclization step allow the reaction to be run under milder conditions, even at room temperature: oleum [323], manganese dioxide in sulfuric acid [324], chlorine in oleum [325], iodine or an inorganic [326] or organic [327] iodine compound in oleum, bis(acetoxyiodo)benzene [328], perborate or percarbonate in sulfuric acid or oleum [329], electrochemical oxidation [330].…”

Azine Dyes

“…Several modifications of the cyclization step allow the reaction to be run under milder conditions, even at room temperature: oleum [321], manganese dioxide in sulfuric acid [322], chlorine in oleum [323], iodine or an inorganic [324] or organic [325] iodine compound in oleum, bis(acetoxyiodo)benzene [326], perborate or percarbonate in sulfuric acid or oleum [327], electrochemical oxidation [328].…”