We report a novel derivative of the conformationally locked derivative of the green fluorescent protein chromophore, (Z)-5-((2-(difluoroboryl)-4-(dimethylamino)phenyl)(4-(dimethylamino)phenyl)methylene)-2-propyl-3,5-dihydro-4H-imidazol-4-on. The presence of an additional aryl substituent in the structure causes a decrease in the fluorescence intensity and does not lead to absorption and emission spectra shifts. A promising direction of research is the replacement of this substituent with the electron-withdrawing groups, such as the nitrile or CF3 group, capable of more efficient conjugation with the π-system of the molecule.