title: Ι₂-mediated amination/cyclization of ketones with 2-aminopyridines under high-speed ball milling: solvent- and metal-free synthesis of 2,3-substituted imidazo[1,2-a]pyridines and zolimidine.
abstract: Under solvent-free high-speed ball milling, an I[Formula: see text]-promoted condensation/cyclization of easily available methyl ketones or 1,3-dicarbonyl compounds with 2-aminopyridines has been developed, which allows the quick assembly of 2,3-substituted imidazo[1,2-a]pyridines (IPs) with broad molecular diversity, including the antiulcer drug zolimidine. The advantages of high yields, good functional group compatibility, short reaction time (within 90 min), free use of heating, solvent and metal, employment of cheap starting materials, and simple work-up procedure make this protocol a very efficient alternative to traditional synthesis of IPs.
authors.affiliation: School of Biological and Chemical Engineering, Anhui Polytechnic University, Wuhu, 241000, Anhui, People's Republic of China.
authors.forename: Fang-Jian
authors.initials: FJ
authors.lastname: Wang
authors.affiliation: School of Biological and Chemical Engineering, Anhui Polytechnic University, Wuhu, 241000, Anhui, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
authors.affiliation: College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, 310014, People's Republic of China.
authors.forename: Ming
authors.initials: M
authors.lastname: Xin
authors.affiliation: School of Biological and Chemical Engineering, Anhui Polytechnic University, Wuhu, 241000, Anhui, People's Republic of China. zhangze@ustc.edu.cn.
authors.forename: Ze
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000586:Amination; D002384:Catalysis; D003500:Cyclization; D007093:Imidazoles / Q000737:chemistry*; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D011725:Pyridines / Q000737:chemistry*; D012997:Solvents
chemical_list: D007093:Imidazoles; D007659:Ketones; D011725:Pyridines; D012997:Solvents; C073260:zolimidine
keywords: Cyclization; Heterocycle synthesis; High-speed ball milling; Imidazo[1, 2-a]pyridines; Iodine; Metal-free; Solvent-free; Zolimidine