DEVELOPMENT OF TRIAZATRUXENE SYNTHESIS USING N-BROMOSUCCINIMIDE

Abstract

Derivatives of triazatruxene (TAT) recently gain much attention for the development of organic optoelectronic materials due to their interesting photophysical properties and high thermal stability. Previous reports on the synthesis of triazatruxene usually rely on cyclocondensation reaction of oxindole or indole, using phosphorus oxychloride or liquid bromine as the reagent. These reagents are highly hazardous, extremely reactive, and exist in liquid form which is inconvenient for storage or uses in large quantities. This research aims to develop a new process for the synthesis of TAT from indole using solid N-bromosuccinimide as the reagent, which should be more users friendly, less hazardous, and more cost-effective than phosphorus oxychloride and bromine. The optimal conditions for this reaction which include solvent, the amount of reagent, reactant concentration, temperature, reaction times and addition method are investigated. Additional experiments are also conducted in order to gain access toward the reaction mechanism. The optimized condition is then used on a larger scale to demonstrate the reproducibility of the process. The scope of the reaction is examined using variously substituted indoles as starting materials.