title: An efficient and convenient synthesis of ethyl 1-(4-methoxyphenyl)-5-phenyl-1H-1,2,3-triazole-4-carboxylate.
abstract: The "click chemistry" of using organic azides and terminal alkynes is arguably the most efficient and straightforward route to the synthesis of 1,2,3-triazoles. In this paper, an alternative and direct access to ethyl 1-(4-methoxyphenyl)-5-phenyl-1H-1,2,3-triazole-4-carboxylate is described. Treatment of ethyl diazoacetate with 4-methoxyaniline derived aryl imines in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene provided fully substituted 1,2,3-triazoles in good to high chemical yields. The base-mediated reaction tolerates various substituted phenyl imines as well as ethyl diazoacetate or the more bulky diazoacetamide. A reasonable mechanism is proposed that involves the addition of an imine nitrogen atom to the terminal nitrogen atom of the diazo compound, followed by aromatization to give the 1,2,3-triazole. The presence of the 4-carboxy group is advantageous as it can be easily transformed into other functional groups.
authors.affiliation: Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan 116, ROC.
authors.forename: Jung-Hsuan
authors.initials: JH
authors.lastname: Chen
authors.forename: Shuan-Ru
authors.initials: SR
authors.lastname: Liu
authors.forename: Kwunmin
authors.initials: K
authors.lastname: Chen
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry; D002264:Carboxylic Acids / Q000138:chemical synthesis* / Q000737:chemistry; D003979:Diazonium Compounds / Q000737:chemistry*; D007097:Imines / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism; D014230:Triazoles / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000814:Aniline Compounds; D002264:Carboxylic Acids; D003979:Diazonium Compounds; D007097:Imines; D014230:Triazoles; C548933:ethyl 1-(4-methoxyphenyl)-5-phenyl-1H-1,2,3-triazole-4-carboxylate; C013813:4-anisidine; C032111:diazoacetic ester