Synthesis of RegioisomericallyPure 5-Functionalized 2′,7′-Dichloro­fluoresceins

Regioisomerically pure 2',7'-dichloro-5-nitrofluorescein was isolated on a multigram scale, and used as an intermediate for the generation of three compounds that might be used for labeling biomolecules, namely the corresponding amino, azido, and (4,6-dichloro-1,3,5-triazin-2-ylamino) derivatives.