A General Approach to Substituted Benzimidazoles and Benzoxazoles
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Heterogeneous Palladium‐Catalyzed Hydrogen‐Transfer with Primary Amines
作者:Marianna Pizzetti、Elisa De Luca、Elena Petricci、Andrea Porcheddu、Maurizio Taddei
DOI:10.1002/adsc.201200253
日期:2012.9.17
employed. Primaryamines are the most suitable reagents for the atom economy of the overall process that resulted to be general as several different substitutedbenzimidazoles were obtained in good yield. Benzoxazoles can be also prepared starting from primaryamines and o‐aminophenol. The reaction is also highly selective as no (poly)‐alkylated phenylenediamines or cross‐contaminated benzimidazoles are
In this and previous studies we investigated the importance of partial structures of Telmisartan on PPAR gamma activation. The biphenyl-4-ylmethyl moiety at N1 and residues at C2 of the central benzimidazole were identified to be essential for receptor activation and potency of receptor binding. Now we focused our attention on positions 5 and 6 of the central benzimidazole and introduced bromine (3b-5/6, 3c), phenylcarbonyl (3d-5/6), hydroxy(phenyl) methyl (3g-5/6), hydroxymethyl (3h-5/6) and formyl (3i) groups. The selection of these moieties was inspired by the structure of Losartan and its metabolite EXP3179. In order to increase the hydrophobicity of the central part of the molecule, the benzimidazole was exchanged by a naphtho[2,3-d] imidazole (5). The compounds 3a-3i and 5 were tested in a differentiation assay using 3T3-L1 preadipocytes and a luciferase assay using COS-7 cells, transiently transfected with pGal4-hPPAR gamma DEF, pGal5-TK-pGL3 and pRL-CMV, as established models for the assessment of cellular PPAR gamma activation. An enhanced effect on PPAR gamma activation could be observed if lipophilic moieties are introduced in these positions. 4 '-[(2-Propyl-1H-naphtho[2,3-d] imidazol-1-yl) methyl] biphenyl-2-carboxylic acid (5) was identified as the most potent compound with an EC50 of 0.26 mu M and the profile of a full agonist.Together with compounds of the former structure-activity relationship study (position 2-substituted benzimidazole derivatives 4a-4j), the binding mode of Telmisartan and its derivatives have been analyzed in 3D pharmacophore-driven docking experiments. (C) 2010 Elsevier Ltd. All rights reserved.
Rhodium catalyzed 2‐alkyl‐benzimidazoles synthesis from benzene‐1,2‐diamines and tertiary alkylamines as alkylating agents
作者:Yamini、Saurabh Sharma、Pralay Das
DOI:10.1002/aoc.6278
日期:2021.8
synthesized from benzene-1,2-diamine and tertiary amines as alkylating agent under polystyrene supported rhodium (Rh@PS) nanoparticles (NPs) catalyzed conditions. The heterogeneous rhodium catalyst was applied first time for the synthesis of 2-alkyl-benzimidazoles. The reaction followed through oxidation of alkylamines, transamination, and oxidativecyclisation with benzene-1,2-diamines for the corresponding
Topoisomerase I inhibition and cytotoxicity of 5-Bromo- and 5-Phenylterbenzimidazoles
作者:Meera Rangarajan、Jung Sun Kim、Sai-Peng Sim、Angela Liu、Leroy F. Liu、Edmond J. LaVoie
DOI:10.1016/s0968-0896(00)00188-7
日期:2000.11
Significant enhancement in the topoisomerase I poisoning activity and cytotoxicity of 5-phenylterbenzimidazole is observed when the 2"-position is substituted with either a chloro or trifluoromethylsubstituent. The influence of such substituents on the biological activity of 5.6-dibromoterbenzimidazole (6a) was also explored. In the case of either 2"-chloro-5,6-dibromoterbenzimidazole (6b) or 2"-trifluoromethyl-5