Regioselectivities in deprotonation of 2-(4-chloro-2-pyridyl) benzoic acid and corresponding ester and amide

AS Rebstock, F Mongin, F Trécourt, G Quéguiner

Index: Rebstock, Anne-Sophie; Mongin, Florence; Trecourt, Francois; Queguiner, Guy Tetrahedron, 2004 , vol. 60, # 10 p. 2181 - 2186

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Citation Number: 17

Abstract

Upon treatment of ethyl 2-(4-chloro-2-pyridyl) benzoic acid, 2-(4-chloro-2-pyridyl) benzoate, and N, N-diisopropyl-2-(4-chloro-2-pyridyl) benzamide with LTMP at− 75° C in THF, the lithio derivatives at C5′ are generated regiospecifically, as demonstrated by subsequent quenching with electrophiles. The lithio derivative at C3′ is only evidenced from the benzamide at higher temperature (− 50° C), when treated with LTMP in THF; it instantly ...