Synthesis and characterization of ethyl benzotriazolyl acrylate-based D–π–A fluorophores for live cell-based imaging applications

A series of eight new ethyl (Z)-benzotriazolyl acrylates 6a-d and 7a-d have been synthesized by conventional heating and microwave irradiation from ethyl benzotriazolyl acetates 3 and 4 with the corresponding aromatic aldehydes. This work reports the synthetic approach and spectroscopic characterization (H-1, C-13-NMR, HRMS) of all the synthesized compounds. X-ray diffraction analyses were performed for molecules 6a, 7a and 7d. Photophysical properties of compounds were evaluated. Finally, compound 6a was tested in a human cell line and showed low to no cytotoxicity at relevant concentrations. Initial testing demonstrates its potential use as a fluid-phase fluorescent marker for live cell imaging.