Design, Synthesis and Evaluation of Fluorescent Properties of Benzothiazole Derivatives

Fluorescence imaging is conducive to establish a bridge between molecular biology and clinical medicine, and provides new tools for disease process research, early diagnosis, and efficacy evaluation, because of the advantages of rapid imaging and nondestructive detection. Herein, a series of fluorescent molecules with thiadiazole, or thiazole, or benzothiazole cores were designed and synthesized to develop more excellent fluorescent molecules in bio‐imaging. According to theoretical and experimental methods, we found that benzothiazole derivative 14 B with conjugate expansion by (4‐aminophenyl) ethynyl group was the most excellent fluorescent molecule among all the investigated compounds and exhibited low cytotoxicity and strong blue and green fluorescence by confocal cell imaging. Benzothiazole derivative 14B with conjugate expansion by (4‐aminophenyl) ethynyl group is synthesized. The compound exhibits higher fluorescence quantum yield, low cytotoxicity, and strong bright green fluorescence during confocal cell imaging.