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.
fluorescence - chromophores - condensation - heterocycles - regioselectivity