A convenient preparation of long chain 4-(4-n-alkylphenylazo)phenols and their 4-pentylbenzoate esters

Abstract

A homologous series of 4-(4-alkylphenylazo)phenols 1[n] (n = 2–22, even) was prepared in yields of 40–70% by Negishi coupling of alkylzinc chlorides with 4-(4-iodophenylazo)phenol (3). The phenols were converted to the corresponding 4-pentylbenzoates 2[n], which exhibit enantiotropic nematic phases even for 2[22].

Keywords:

• azobenzene; homologous series; synthesis

Acknowledgements

Financial support for this work was received from the National Science Foundation (DMR-0606317).