Metal-Free Nitration of Indazoles with tert-Butyl Nitrile in Air to Prepare 3-Nitroindazoles and 3-Aminoindazoles  

作　　者：Xin-Yue Zhang Rong-Ting Jiang Xiu-Qun Pan Chun-Hua Chen Cui Liang Dong-Liang Mo 

机构地区：[1]State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources,Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources(Ministry of Education of China),Collaborative Innovation Center for Guangxi Ethnic Medicine,School of Chemistry and Pharmaceutical Sciences,Guangxi Normal University,15 Yu Cai Road,Guilin,Guangxi 541004,China [2]Key Laboratory of Chemistry and Engineering of Forest Products,State Ethnic Affairs Commision,Guangxi Key Laboratory of Chemistry and Engineering of Forest Products,Guangxi Collaborative Innovation Center for Chemistry and Engineering of Forest Products,Schoolof Chemistry and Chemical Engineering,Guangxi Minzu University,Nanning,Guangxi 530006,China

出　　处：《Chinese Journal of Chemistry》2025年第4期393-398,共6页中国化学(英文版)

基　　金：the NSFC(22071035);Natural Science Foundation of Guangxi(2023GXNSFDA026025);Guangxi Bagui Young Scholar is greatly appreciated.

摘　　要：A variety of 3-nitroindazoles and 3-aminoindazoles were prepared in good to excellent yields with high regioselectivity through TBN-mediated nitration at the C3-position of indazoles under the air conditions and sequential reduction.Mechanistic studies revealed that TBN played crucial roles to produce·NO_(2) radical source in the presence of air conditions and C3-nitration of indazoles was initiated by N1-nitration and sequential migration of NO_(2) group to C3-position.Moreover,this method could be easily applied in the gram scalable synthesis of ibuprofen and ciprofibrate-derived 3-aminoindazoles.The present method highlights air as mild oxidant,metal-free radical nitration of indazole,N—N bond formation and cleavage,and late-stage modification of drugs.

关 键 词：NITRATION INDAZOLE 3-Nitroindazole 3-Aminoindazole C-H Amination Radical reactions N-HETEROCYCLES Cleavage reactions 

分 类 号：R36[医药卫生—病理学]