Synthesis of ethyl 3-phenyl-4-(trifluoromethyl) isoxazole-5-carboxylate via regioselective dipolar cycloaddition

MA Schmidt, K Katipally, A Ramirez, O Soltani, X Hou…

Index: Schmidt, Michael A.; Katipally, Kishta; Ramirez, Antonio; Soltani, Omid; Hou, Xiaoping; Zhang, Huiping; Chen, Bang-Chi; Qian, Xinhua; Deshpande, Rajendra P. Tetrahedron Letters, 2012 , vol. 53, # 31 p. 3994 - 3997

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Citation Number: 10

Abstract

Efforts to prepare ethyl 3-phenyl-4-(trifluoromethyl) isoxazole-5-carboxylate (1) by developing a regioselective 1, 3-dipolar cycloaddition between phenyl nitrile oxide and various 4, 4, 4-trifluoromethyl crotonates are described. The substitution at the C2-position of crotonate dipolarophile 4 significantly influenced the regiochemistry and yield of the cycloaddition. Enol and enol ether-based crotonates underwent regioselective ...