Separation of the 5- and 6-Carboxy Regioisomers of ROX and JOE Dyes with Examples of N-(3-Azidopropyl)amide Synthesis

Abstract

Despite the widespread applications of various rhodamine and fluorescein 5- and 6-carboxy derivatives, the preparation of their pure regioisomers, in particular cases, remains a complex task. In the present paper we propose optimized approaches to the synthesis and separation of these isomers of ROX and JOE dyes, and also demonstrate their applicability in the synthesis of the corresponding N-(3-azidopropyl)amides.