Design and synthesis of a new indazole library: direct conversion of N-methoxy-N-methylamides (Weinreb amides) to 3-keto and 3-formylindazoles

F Crestey, S Stiebing, R Legay, V Collot, S Rault

Index: Crestey, Francois; Stiebing, Silvia; Legay, Remi; Collot, Valerie; Rault, Sylvain Tetrahedron, 2007 , vol. 63, # 2 p. 419 - 428

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Citation Number: 17

Abstract

Nucleophilic addition of Grignard or lithiated reagents on the new Weinreb amides 3 and 4 afforded efficiently the corresponding ketones and allowed the design and synthesis of a new indazole library. These 3-ketoindazoles were obtained by a direct and original conversion of N-methoxy-N-methylamides with good yields. Furthermore, the reduction of 3 with LiAlH4 furnished the corresponding aldehydes as a versatile and efficient pathway to ...