Regioselective microwave-assisted synthesis of substituted pyrazoles from ethynyl ketones

被引：56

作者：

Bagley, Mark C.

Lubinu, M. Caterina

Mason, Christopher

机构：

[1] Univ Cardiff Wales, Sch Chem, Cardiff CF10 3AT, Wales

[2] CEM Microwave Technol Ltd, Buckingham MK18 1WA, England

来源：

SYNLETT | 2007年 / 05期

基金：

英国工程与自然科学研究理事会;

关键词：

ethynyl ketones; pyrazoles; heterocycles; microwave synthesis; concurrent heating and cooling;

D O I：

10.1055/s-2007-970783

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Reaction of alpha,beta-ethynyl ketones and hydrazine derivatives gives 1,3- and 1, 5 -disubstituted pyrazoles in good yield. Microwave irradiation in concentrated hydrochloric acid-methanol (1.5% v/v), with concurrent cooling at sub-ambient temperatures or at 120 degrees C, for 30 or 2 minutes, respectively, facilitates rapid heterocyclization and preferentially gives the 1,3 -disubstituted regioisomer.

引用

页码：704 / 708

页数：5

共 41 条

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