A One‐pot Approach to Ethyl 1,4,5‐Triaryl‐1 H ‐pyrazole‐3‐carboxylates via an Improved Claisen Condensation‐Knorr Reaction Sequence

Abstract A one‐pot approach to ethyl 1,4,5‐triaryl‐1 H ‐pyrazole‐3‐carboxylates has been developed in moderate to high yields. The tert ‐BuOLi‐mediated Claisen condensation of 1,2‐diarylethanones and ethyl oxalyl chloride efficiently provided the enolized lithium salts of ethyl 2,4‐dioxo‐3,4‐diarylb...

Full description

Saved in:
Bibliographic Details
Published inChinese journal of chemistry Vol. 31; no. 12; pp. 1526 - 1538
Main Authors Zhai, Jiaojiao, Gu, Chunhui, Jiang, Jianan, Zhang, Shunli, Liao, Daohua, Wang, Lei, Zhu, Dunru, Ji, Yafei
Format Journal Article
LanguageEnglish
Published 01.12.2013
Online AccessGet full text

Cover

More Information
Summary:Abstract A one‐pot approach to ethyl 1,4,5‐triaryl‐1 H ‐pyrazole‐3‐carboxylates has been developed in moderate to high yields. The tert ‐BuOLi‐mediated Claisen condensation of 1,2‐diarylethanones and ethyl oxalyl chloride efficiently provided the enolized lithium salts of ethyl 2,4‐dioxo‐3,4‐diarylbutanoates, which in situ reacted with arylhydrazine hydrochlorides via a hydrochloric acid‐promoted Knorr reaction to produce the exquisite triarylpyrazole‐3‐carboxylates. The procedure promises a convenient access to this highly crowded framework for drug discovery.
ISSN:1001-604X
1614-7065
DOI:10.1002/cjoc.201300776