Synlett, Inhaltsverzeichnis Synlett 2019; 30(12): 1469-1473DOI: 10.1055/s-0037-1611847 letter © Georg Thieme Verlag Stuttgart · New York Copper Acetate Aerobic Oxidative Synthesis of Pyrido[1,2-a]benzimidazoles from Aminopyridines and Phenylboronic Acids Hao Yan* a College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang 712046, P. R. of China eMail: yanhao@sntcm.edu.cn b State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. of China , Hui Guo a College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang 712046, P. R. of China eMail: yanhao@sntcm.edu.cn , Xiaoqiang Zhou b State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. of China c College of Chemistry and Materials, Weinan Normal University, Chaoyang Road, Weinan 714099, P. R. of China , Zhenyu Zuo a College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang 712046, P. R. of China eMail: yanhao@sntcm.edu.cn , Jingli Liu a College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang 712046, P. R. of China eMail: yanhao@sntcm.edu.cn , Guanghui Zhang a College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang 712046, P. R. of China eMail: yanhao@sntcm.edu.cn , Shuan Zhang a College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang 712046, P. R. of China eMail: yanhao@sntcm.edu.cn › Institutsangaben Artikel empfehlen Abstract Artikel einzeln kaufen Alle Artikel dieser Rubrik Abstract Pyrido[1,2-a]benzimidazoles, which show interesting and potentially useful biological activities, have drawn extensive attention from chemists. A straightforward copper acetate-oxidative one-pot synthesis of these compounds from 2-aminopyridines and phenylboronic acids through C–N bond formation and C–H bond activation was developed as a simple and convenient method. Key words Key wordsoxidation - cyclization - N–H coupling - C–H activation - pyridobenzimidazoles Volltext Referenzen References and Notes 1 Bagdi AK, Santra S, Monir K, Hajra A. Chem. Commun. 2015; 51: 1555 2a Rupert KC, Henry JR, Dodd JH, Wadsworth SA, Cavender DE, Olini GC, Fahmy B, Siekierka J. Bioorg. Med. Chem. Lett. 2003; 13: 347 2b Moraski GC, Markley LD, Hipskind PA, Boshoff H, Cho S, Franzblau SG, Miller MJ. ACS Med. Chem. Lett. 2011; 2: 466 3 Bae J.-S, Lee D.-W, Lee D.-H, Jeong D.-S. WO 2007011163, 2007 4 Takeshita H, Watanabe J, Kimura Y, Kawakami K, Takahashi H, Takemura M, Kitamura A, Someya K, Nakajima R. Bioorg. Med. Chem. Lett. 2010; 20: 3893 5 Refaat HM. Med. Chem. 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The Schlenk tube was sealed and then evacuated and backfilled with O2 (three cycles). DMSO (2 mL) was added, and the mixture was stirred at 120 °C for 36 h then cooled to r.t. The solvent was diluted with EtOAc (10 mL), and the mixture was washed with brine (5 mL) then dried (Na2SO4) and concentrated under vacuum. The residue was purified by column chromatography (silica gel, PE–EtOAc) to give a yellow solid; yield: 43 mg (80%); mp 174–176 °C. IR (neat): 3057, 3018, 1641, 1502, 1466, 1356, 1258, 1226, 1144, 756, 723 cm–1. 1H NMR (400 MHz, CDCl3): δ = 8.42 (dd, J = 6.8, 1.2 Hz, 1 H), 7.94 (d, J = 8.4 Hz, 1 H), 7.86 (d, J = 8.0 Hz, 1 H), 7.68 (dd, J = 9.2, 0.8 Hz, 1 H), 7.54–7.51 (m, 1 H), 7.42–7.34 (m, 2 H), 6.82 (t, J = 6.8 Hz, 1 H). 13C NMR (100 MHz, CDCl3): δ = 148.4, 144.5, 129.2, 128.6, 125.6, 125.1, 120.9, 119.9, 118.0, 110.3, 110.2. HRMS (ESI): m/z [M + H]+ calcd for C11H9N2: 169.0760; found: 169.0757. 21 Han Y, Zhang M, Zhang Y.-Q, Zhang Z.-H. 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