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An Efficient and Convenient Synthesis of Ethyl 1‐(4‐Methoxyphenyl)‐5‐phenyl‐1 H ‐1,2,3‐triazole‐4‐carboxylate
Author(s) -
Chen JungHsuan,
Liu ShuanRu,
Chen Kwunmin
Publication year - 2010
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.200900320
Subject(s) - chemistry , aromatization , imine , carboxylate , ethyl diazoacetate , diazo , nitrogen atom , triazole , combinatorial chemistry , medicinal chemistry , catalysis , organic chemistry , cyclopropanation , group (periodic table)
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‐1 H ‐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.