Synthesis of new benzothiazoles, benzoxazoles, and benzo [1, 3]-dithiols by Ullmann coupling of dihalobenzene and nitro compounds-heterocumulene adducts

Abstract

In this contribution, a simple and fast method for the synthesis of various types of benzothiazoles, benzoxazoles, and benzo[1,3]-dithioles using Ullman coupling reaction of dihalobenzene and nitro-heterocumulene compounds in the vicinity of copper catalyst, Cs₂CO₃ as the base, and highly efficient was successfully implemented without the help of an additional ligand under ultrasound irradiation. The use of simple and readily available starting materials, mild copper-catalytic reaction conditions, no column chromatography, good yields, applying the sonochemical methodology, and short reaction times are remarkable specifications of this protocol.

Graphical abstract