4-Lithio-4'-alkylazobenzenes as Convenient Intermediates for the Preparation of Azobenzene Derivatives

Abstract

The first successful generation of lithioazobenzenes from bromoazobenzenes utilizing the Köbrich-Buck halogen-lithium exchange is described. The aryl anions formed were trapped with a great variety of different electrophiles (deuterium oxide, acetone, benzaldehyde, 5,5-diethoxypentan-2-al, bromotrimethylsilane and dimethylformamide) to provide the respective 4-substituted azobenzene derivatives.