Synthesis of azobenzenes from quinone acetals and arylhydrazines

J Org Chem. 2004 May 14;69(10):3413-6. doi: 10.1021/jo0498011.

Abstract

Direct reaction between quinone bisacetals and arylhydrazines gives azobenzenes. The presence of catalytic amounts of cerium ammonium nitrate strongly accelerates the reaction. When the bisacetal has a substituent at the 2,5-cyclohexadiene framework, only one regioisomer is formed. The method represents a simple, mild, and novel synthetic access to differently substituted azocompounds in high to excellent yield.