Synthesis, Table of Contents Synthesis 2012; 44(20): 3231-3237DOI: 10.1055/s-0032-1317131 paper © Georg Thieme Verlag Stuttgart · New YorkAn Efficient C–H Arylation of a 5-Phenyl-1H-tetrazole Derivative: A Practical Synthesis of an Angiotensin II Receptor Blocker Authors Author Affiliations Masahiko Seki* Mitsubishi Tanabe Pharma Corporation, 2-6-18, Kitahama, Chuo-ku, Osaka 541-8505, Japan, Fax: +81(6)62013150 Email: seki.masahiko@mm.mt-pharma.co.jp Recommend Article Abstract Buy Article(opens in new window) All articles of this category(opens in new window) Abstract An efficient protocol for C–H arylation of 1-benzyl-5-phenyl-1H-tetrazole has been developed which involves an extremely small amount of commercially available [RuCl2(p-cymene)]2 (Ru: 0.63 mol%) and a specific amount of triphenylphosphine (ratio Ph3P/Ru 2:1). The obtained biphenyl derivative was readily elaborated to give candesartan cilexetil, a potent angiotensin II receptor blocker by means of an efficient removal of the benzyl protecting group by palladium on carbon catalyzed transfer hydrogenation in the final step. Key words Key wordsgreen chemistry - C–H activation - ruthenium - drug synthesis - protecting groups Full Text References References 1a The Art of Process Chemistry . Yasuda N. Wiley-VCH; Weinheim: 2011 1b Anderson NG. Practical Process Research & Development . Academic Press; Oxford: 2000 1c Green Chemistry in the Pharmaceutical Industry . Dunn P, Wells A, Williams MT. Wiley-VCH; Weinheim: 2010 For selected examples: see, reviews: 2a Daugulis O, Do J.-Q, Shabashov D. Acc. Chem. Res. 2009; 42: 1074 2b Chen X, Engle KM, Wang D.-H, Yu J.-Q. Angew. Chem. Int. Ed. 2009; 48: 5094 2c Ackermann L, Vicente R, Kapdi AR. Angew. Chem. Int. Ed. 2009; 48: 9792 2d Willis MC. Chem. Rev. 2010; 110: 725 2e Mkhalid IA. 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