An Efficient One-pot Synthesis of Aryl-substituted 1-(Thiazol-2-yl)-1H-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 

机构地区：[1]School of Pharmacy,East China University of Science and Technology,Shanghai 200237,China [2]State Key Laboratory of Materials-Oriented Chemical Engineering,College of Chemistry and Chemical Engineering,Nanjing University of Technology,Nanjing,Jiangsu 210009,China

出　　处：《Chinese Journal of Chemistry》2014年第2期179-190,共12页中国化学（英文版）

基　　金：The authors are grateful to the National Natural Science Foundation of China(Nos.21176074 and 21171093)for financial support.

摘　　要：The treatment ofα-bromoalkyl aryl ketones and 2-(propan-2-ylidene)hydrazine 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)-1Hpyrazole-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 salt,were synthesized in situ by a high-yield tert-BuOLi-mediated Claisen condensation of alkylphenones and diethyl oxalate.This class of elegant molecule comprises aryl groups on the two different heterocyclic cores,and the configurations of two representative molecules were determined by single crystal X-ray crystallography.

关 键 词：one-pot synthesis Claisen condensation Hantzsch synthesis Knorr reaction 1-(thiazol-2-yl)pyrazole-3-carboxylates 

分 类 号：O62[理学—有机化学]