Synthesis of 2-aryl-1-hydroxy-1H-naphtho[2,3-d]imidazole-4,9-diones by reaction of 2-benzylamino-1,4-naphthoquinones with nitric acid

Naphthoquinone-based imidazolyl esters as blue-light-sensitive Type I photoinitiators

“…Following reaction with benzylamine (C2) and 3,4-dimethoxybenzylamine (C3), products 2-(benzylamino)naphthalene-1,4-dione (C4) and 2-((3,4-dimethoxylbenzyl)amino) naphthalene-1,4-dione (C5) were afforded in 92 and 85% yields, respectively. Using a cyclization reaction previously reported by Lavrikova and coworkers, 28 completed in acetic acid, and following treatment with a mixture of nitric and sulfuric acids, 1-hydroxy-2-phenyl-1 H -naphtho[2,3- d ]imidazole-4,9-dione (C6) and 2-(3,4-dimethoxyphenyl)-1-hydroxy-1 H -naphtho[2,3- d ]imidazole-4,9-dione (C7) could be obtained in 67 and 84% yields, respectively. 1-Hydroxy-2-phenyl-1 H -naphtho[2,3- d ]imidazole-4,9-dione derivatives C6 and C7 were then esterified with different acid chlorides using triethylamine as the base, providing compounds 2–15 .…”

Synthesis andIn VitroBiological Evaluation of Aminonaphthoquinones and Benzo[b]phenazine-6,11-dione Derivatives as Potential Antibacterial and Antifungal Compounds

“…Quinones are active compounds used widely as raw materials in pharmaceuticals and agrochemical industries. Particularly, (hetero)cyclic quinone moieties not only exist in many natural products and pharmaceutical compounds, but also are well-known and versatile building blocks for the synthesis of quinones derived from benzoquinone, naphthoquinone, or anthracenequinone condensed with five-membered heterocycles [1][2][3] such as isoxazoles [4], six-membered heterocycles [3,5], and seven-membered heterocycles [6,7] such as 1,4-benzodiazepines [8] in order to evaluate their important bioactivities. Therefore, among the bioactive quinones, 1,4naphthoquinones have been extensively studied since those ones contain two ketone groups as a crucial pharmacophore for their bioactivities because of their ability to accept electrons [9].…”