Abstract
Convenient and efficient synthesis of a new environmentally sensitive chlorine-substituted 2,3-naphthalimide-based fluorophore is reported. Benzotriazole carboxyl group activation of the 6-chloro-fluorophore enabled quick labeling of free and Fmoc-protected amino acids. The photophysical properties of the compounds obtained include high quantum yields in solvents of different polarity: water, methanol, acetonitrile and hexane.