A New Procedure for Preparation of Carboxylic Acid Hydrazides
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- 作者：Xini Zhang ; Michael Breslav ; Jeffrey Grimm ; Kailin Guan ; Aihua Huang ; Fuqiang Liu ; Cynthia A. Maryanoff ; David Palmer ; Mitul Patel ; Yun Qian ; Charles Shaw ; Kirk Sorgi ; Stephen Stefanick ; and Dawei Xu
- 刊名：Journal of Organic Chemistry
- 出版年：2002
- 出版时间：December 27, 2002
- 年：2002
- 卷：67
- 期：26
- 页码：9471 - 9474
- 全文大小：85K
- 年卷期：v.67,no.26(December 27, 2002)
- ISSN：1520-6904
文摘
The standard method for preparing carboxylicacid hydrazides is hydrazinolysis of esters in alcoholicsolutions. However, when applied to 
,
-unsaturated esters,the main product typically is the pyrazolidinone resultingfrom an undesired Michael-type cyclization. Other alternative methodologies reported for direct preparation of hydrazides from acids are inefficient. We developed an efficientand general process, involving preforming activated estersand/or amides followed by reaction with hydrazine, for thepreparation of hydrazides including those of ,-unsaturatedacids. This process gives the desired hydrazides in excellentyield and purity under mild conditions.
,-unsaturated esters,the main product typically is the pyrazolidinone resultingfrom an undesired Michael-type cyclization. Other alternative methodologies reported for direct preparation of hydrazides from acids are inefficient. We developed an efficientand general process, involving preforming activated estersand/or amides followed by reaction with hydrazine, for thepreparation of hydrazides including those of ,-unsaturatedacids. This process gives the desired hydrazides in excellentyield and purity under mild conditions.