作者:Richard J. Fox、Michael A. Schmidt、Martin D. Eastgate
DOI:10.1021/acs.joc.7b03282
日期:2018.3.2
A general strategy to prepare substituted 3-bromo- and 3-chloropyrazoles is described. The three-step method involves condensation of crotonates or β-chloro carboxylic acids with hydrazines, followed by halogenation and oxidation. Several condensation and oxidation protocols were developed to enable preparation of a wide variety of 3-halopyrazoles with good to excellent yields and regiocontrol.
描述了制备取代的3-溴和3-氯吡唑的一般策略。三步法涉及将巴豆酸酯或β-氯代羧酸与肼缩合,然后进行卤化和氧化。已开发了几种缩合和氧化方案,以能够制备各种3-卤代吡唑,并具有良好或优异的收率和区域控制能力。