Renáta Farkas

Synthesis of new 2-(2′-hydroxyaryl)benzotriazoles and evaluation of their photochemical behavior as potential UV-filters

Two new 2-(2´-hydroxyaryl)benzotriazole derivatives were synthesized and studied by photophysical and photochemical techniques in order to assess their ability to act as UV-filters. The absorption and emission properties of both compounds were determined in solvents of different polarity. In non polar solvent, a photoinduced excited state intramolecular proton transfer was established leading to efficient non radiative dissipation of UV-energy. In addition, the compounds considered were photostable under irradiation with simulated sunlight.

Simultaneous displacement of a nitro group during coupling of diazotized o-nitroaniline with phenols

During the diazo-coupling reaction, nucleophilic displacement of a nitro group was also observed. This was the main reaction (1→7) when the starting amine bore either a chlorine or methoxy group at the para position (1b–c). The newly prepared compounds (7) might serve as convenient building blocks in synthesis of some heterocycles.

One-pot synthesis of benzotriazoles and benzotriazole 1-oxides by reductive cyclization of o-nitrophenylazo compounds with benzyl alcohol

Reductive cyclization of 2-[(2-nitrophenyl)azophenols 1 with benzyl alcohol and sodium hydroxide afforded 2-(2H-benzotriazol- 2-yl)phenols 3 and their 1-oxide 2 in good to excellent yields.