A New Procedure for Preparation of Carboxylic Acid Hydrazides

• Published in: Journal of organic chemistry Vol. 67; no. 26; pp. 9471 - 9474
• Main Authors: Zhang, Xini, Breslav, Michael, Grimm, Jeffrey, Guan, Kailin, Huang, Aihua, Liu, Fuqiang, Maryanoff, Cynthia A, Palmer, David, Patel, Mitul, Qian, Yun, Shaw, Charles, Sorgi, Kirk, Stefanick, Stephen, Xu, Dawei
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 27.12.2002; Amer Chemical Soc
• Subjects: Aliphatic compounds; Chemistry; Chemistry, Organic; Exact sciences and technology; Organic chemistry; Physical Sciences; Preparations and properties; Science & Technology; DERIVATIVES; INHIBITION; Organic hydrazide; Ester; Acetylenic compound; Carboxylic acid; Amides; Hydrazine; Chemical synthesis; Organic carbamate; Ethylenic compound
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo026288n

The standard method for preparing carboxylic acid hydrazides is hydrazinolysis of esters in alcoholic solutions. However, when applied to α,β-unsaturated esters, the main product typically is the pyrazolidinone resulting from an undesired Michael-type cyclization. Other alternative methodologies reported for direct preparation of hydrazides from acids are inefficient. We developed an efficient and general process, involving preforming activated esters and/or amides followed by reaction with hydrazine, for the preparation of hydrazides including those of α,β-unsaturated acids. This process gives the desired hydrazides in excellent yield and purity under mild conditions.