Synthesis of 3??(Tosylalkyl) indazoles and their Desulfonylation Reactions–A New Entry to 3??Substituted Indazoles by an Unprecedented Friedel–Crafts Process

S Campetella, A Palmieri…

Index: Campetella, Silvia; Palmieri, Alessandro; Petrini, Marino European Journal of Organic Chemistry, 2009 , # 19 p. 3184 - 3188

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Citation Number: 4

Abstract

Abstract Reaction of indazoles with aldehydes in the presence of p-toluenesulfinic acid affords the corresponding sulfonyl indazoles in satisfactory yields. The reported Friedel– Crafts process is rather unusual on indazoles because of the reduced electronic density of the heterocycle. The obtained sulfonyl indazoles can be desulfonylated under reductive conditions, finally leading to 3-alkylated indazoles.(© Wiley-VCH Verlag GmbH & Co. ...