A novel method for the synthesis of benzimidazole-based 1,4-quinone derivatives

Synthesis of Pyrimidine- and Quinazoline-Fused Benzimidazole-4,7-diones Using Combinatorial Cyclocondensation and Oxidation

“…HRMS (EI): calcd for C 16 H 17 N 3 O 2 (M + ), 283.1321;found, 283.1318. 8,11-Dimethoxy-3-methyl-1,2,3,4-tetrahydrobenzo[4,5]imidazo [1,2-a] 28.9, 30.6, 33.2, 34.6, 55.8, 56.9, 100.8, 106.2, 116.4, 117.4, 133.5, 136.8, 143.4, 145.6, 149.5, 165.6 8,2,3,5]imidazo [1,2-a]quinazoline (3c). R f = 0.32.…”

“…It is reported that N-fused hybrid scaffold A can be synthesized by the reaction of 2-aminopyrimidine with p -chloranil (2,3,5,6-tetrachloro-1,4-benzoquinone) followed by subsequent treatment with diethylamine and HCl (Scheme ). We reported on the synthesis of N-fused hybrid scaffold B by step-by-step copper-catalyzed coupling and cyclization of 2-(2-bromovinyl)-4,7-dimethoxybenzimidazoles with primary amides to form pyrimidine-fused 4,7-dimethoxybenzimidazoles, and oxidation of such intermediates by aqueous ceric ammonium nitrate (CAN) (Scheme ). As part of our continuing studies directed toward transition metal–catalyzed and transition metal–free cyclization reactions for heterocycles, we have shown several new synthetic protocols for N-fused hybrid scaffolds .…”

Synthesis of Binuclear Isoquinoline‐ and Pyridine‐Fused Benzimidazole‐4,7‐diones by Magnetic MOF‐199‐Catalyzed C–C Coupling/Cyclization Followed by Oxidation

“…It is also known that a class of homonuclear benzimidazole‐based 1,4‐quinones (1 H –benzo[ d ]imidazole‐4,7‐diones) exhibit a wide range of biological activities, such as cytotoxic, antitumor, anticancer, and antiproliferative activities and apply to the development of bioreductive quinone‐based drugs , . However, except for one report for the synthesis of pyridine‐fused benzimidazole‐4,7‐diones (Scheme , D ), no reports are found for the synthetic route and biological activity of binuclear isoquinoline‐fused benzimidazole‐4,7‐diones (Scheme , C ). During the course of our efforts directed toward transition metal–catalyzed and transition metal‐free cyclization reactions, we recently focused on developing new synthetic methods for binuclear and trinuclear N‐fused hybrid scaffolds .…”

Synthesis of N-Fused Benzimidazole-4,7-diones via Sequential Copper-Catalyzed C–N Coupling/Cyclization and Oxidation

“…Only one example for the synthesis of N-fused hybrid analogue of C , benzo[4,5]imidazo[1,2- a ]pyrimidin-6,9-dione, is known. 10 However, several [1,2- a ]alicyclic ring-fused benzimidazolequinones have been synthesized and tested for biological activity. 11 Benzimidazole-based 1,4-quinone (1 H -benzo[ d ]imidazole-4,7-dione)-containing compounds has received pivotal attention in the development of bioreductive quinone-based drugs due to a wide spectrum of biological activities, such as anticancer, cytotoxic, antitumor, and antiproliferative activities.…”