3??Aroyl??5??hydroxyflavones: Synthesis and Transformation into Aroylpyrazoles

…, A Silva, LMPM Almeida, JAS Cavaleiro…

Index: Pinto, Diana C. G. A.; Silva, Artur M. S.; Almeida, Lucia M. P. M.; Cavaleiro, Jose A. S.; Elguero, Jose European Journal of Organic Chemistry, 2002 , # 22 p. 3807 - 3815

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Citation Number: 13

Abstract

Abstract Treatment of 3-aroyl-5-benzyloxyflavones 4a− e with hydrazine afforded 3, 5-diaryl- 4-(2-benzyloxy-6-hydroxybenzoyl) pyrazoles 5a− e, together with 4-aroyl-5-aryl-3-(2- benzyloxy-6hydroxyphenyl) pyrazoles 6a− e as minor products. The structures of all new compounds have been established by extensive NMR studies and the reaction mechanisms are discussed.(© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)