An Efficient and Convenient Synthesis of Ethyl 1-(4-Methoxyphenyl)-5-phenyl-1H-1,2,3-triazole-4-carboxylate

作者：Chen Jung Hsuan; Liu Shuan Ru; Chen Kwunmin^*

来源：Chemistry-An Asian Journal, 2010, 5(2): 328-333.

DOI：10.1002/asia.200900320

• aromaticity
• cycloaddition
• diazo compounds
• heterocycles
• triazoles

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.

• 出版日期2010