Synthesis of 7-trifluoromethylpyrazolo [1, 5-a] pyridinedicarboxylate

P Chong, R Davis, V Elitzin, M Hatcher, B Liu…

Index: Chong, Pek; Davis, Roman; Tabet, Elie; Elitzin, Vassil; Hatcher, Mark; Liu, Bing; Salmons, Matthew Tetrahedron Letters, 2012 , vol. 53, # 50 p. 6786 - 6788,3

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Citation Number: 7

Abstract

Two syntheses of 7-trifluoromethylpyrazolo [1, 5-a] pyridine dicarboxylate have been described. Approach A utilizes a nucleophilic addition of a trifluoromethyl group to Np- toluenesulfonyliminopyridinium ylide followed by aromatization and subsequent cycloaddition with diethyl acetylenedicarboxylate to give 1b in modest yield. Approach B involves a selective zincation of pyrazolopyridine dicarboxylate at the C7 position with ( ...