An Efficient One-pot Synthesis of Aryl-substituted 1-(Thiazol-2-yl)-1<i>H</i>-pyrazole-3-carboxylates via a Hantzsch Synthesis-Knorr Reaction Sequence
作者:Chunhui Gu、Jiaojiao Zhai、Jianan Jiang、Hongwei Liu、Lei Wang、Dunru Zhu、Yafei Ji
DOI:10.1002/cjoc.201300878
日期:2014.2
carbothioamide afforded 4‐aryl‐2‐(2‐(propan‐2‐ylidene)hydrazinyl)thiazoles via a Hantzsch‐thiazole synthesis, which reacted with 4‐aryl‐2,4‐diketoesters via a sequential Knorr‐pyrazole reaction to deliver a variety of aryl‐substituted ethyl 1‐(thiazol‐2‐yl)‐1H‐pyrazole‐3‐carboxylates in a one‐pot fashion with moderate to high yields. The key intermediates 4‐aryl‐2,4‐diketoesters, existing as its enolic lithium
通过Hantzsch-噻唑合成反应处理α-溴代烷基芳基酮和2-(丙烷-2-亚烷基)肼碳硫代酰胺得到4-芳基-2-(2-(丙烷-2-亚烷基)肼基)噻唑通过顺序的克诺尔-吡唑反应以单锅方式以适度的温和性输送各种芳基取代的1-(噻唑-2-基)-1H-吡唑-3-羧酸酯的4-芳基-2,4-二酮酸酯高产。现有的关键中间体4-芳基-2,4-二酮酸酯是烯醇式锂盐,是通过烷基苯酮和草酸二乙酯的高产率叔丁基醇介导的克莱森缩合反应原位合成的。这类优雅的分子在两个不同的杂环核上均包含芳基,并且两个代表性分子的构型是通过单晶X射线晶体学确定的。