An improved synthesis of substituted dibenzo[l,4]dioxines

Abstract

An improved general synthesis of substituted dibenzo[1,4]dioxines by reaction of catechol and substituted 1,2-dichloro- or 2-chloronitro-benzenes with metallic potassium in hexamethylphosphoramide is reported. The yields are generally superior to those in published methods, and in particular the reaction appears the one of choice for the synthesis of both the parent dibenzodioxine and the 1-carboxy derivative.