Base mediated 1,3-dipolar cycloaddition of α-substituted vinyl phosphonates with diazo compounds for synthesis of 3-pyrazolylphosphonates and 5-pyrazolcarboxylates
作者:Nataliya S. Goulioukina、Nikolay N. Makukhin、Egor D. Shinkarev、Yuri K. Grishin、Vitaly A. Roznyatovsky、Irina P. Beletskaya
DOI:10.1039/c6ob01780k
日期:——
5-Aryl-substituted pyrazol-3-ylphosphonates have been conveniently synthesized by 1,3-dipolar cycloaddition of 1-formamidovinylphosphonates and aryldiazomethanes under K2CO3/MeOH conditions at room temperature. These pyrazoles are formed in one pot via spontaneous elimination of formamide. Basic conditions prevent competitive formation of cyclopropylphosphonates. 3-Aryl substituted pyrazol-5-carboxylates
通过在室温下在K 2 CO 3 / MeOH条件下将1-甲酰胺基乙烯基膦酸酯和芳基重氮甲烷进行1,3-偶极环加成,可以方便地合成5-芳基取代的吡唑-3-基膦酸酯。这些吡唑是通过自发消除甲酰胺而在一锅中形成的。碱性条件阻止竞争性形成环丙基膦酸酯。3-芳基取代的吡唑-5-羧酸酯可以通过相同的方法由1-芳基乙烯基膦酸酯和重氮乙酸乙酯合成,尽管为了确保芳构化阶段成功且消除二乙氧基磷酰基部分是必需的,更强的碱NaH是必需的。
One-pot synthesis of pyrazole-5-carboxylates by cyclization of hydrazone 1,4-dianions with diethyl oxalate
作者:Tuan Thanh Dang、Tung Thanh Dang、Peter Langer
DOI:10.1016/j.tetlet.2007.03.093
日期:2007.5
The cyclization of hydrazone dianions with diethyl oxalate afforded pyrazole-5-carboxylates.
用草酸二乙酯对的二价阴离子进行环化,得到吡唑-5-羧酸酯。
Synthesis of pyrazole-3-carboxylates and pyrazole-1,5-dicarboxylates by one-pot cyclization of hydrazone dianions with diethyl oxalate
作者:Tung T. Dang、Tuan T. Dang、Christine Fischer、Helmar Görls、Peter Langer
DOI:10.1016/j.tet.2007.12.024
日期:2008.2
The one-pot cyclization of hydrazone dianions with diethyl oxalate allows a convenient synthesis of pyrazole-3-carboxylates and pyrazole-1,5-dicarboxylates.
与草酸二乙酯的一锅法二价环化反应可以方便地合成吡唑-3-羧酸盐和吡唑-1,5-二羧酸盐。
Cascade regioselective synthesis of pyrazoles from nitroallylic acetates and N-tosyl hydrazine
作者:Nana Shao、Tong Chen、Taotao Zhang、Huajian Zhu、Qunxiong Zheng、Hongbin Zou
DOI:10.1016/j.tet.2013.12.046
日期:2014.1
A simple, practical, and regioselective synthetic protocol for the formation of pyrazoles was developed. Unlike all other previously reported reactions of nitroallylic acetates, this process was initiated by a S(N)2 reaction at the electrophilic gamma site. A plausible mechanism for the cascade S(N)2-Michael synthesis is proposed. (C) 2013 Elsevier Ltd. All rights reserved.
Utilization of an Active Site Mutant Receptor for the Identification of Potent and Selective Atypical 5-HT<sub>2C</sub> Receptor Agonists
作者:Joseph Carpenter、Ying Wang、Gang Wu、Jianxin Feng、Xiang-Yang Ye、Christian L. Morales、Matthias Broekema、Karen A. Rossi、Keith J. Miller、Brian J. Murphy、Ginger Wu、Sarah E. Malmstrom、Anthony V. Azzara、Philip M. Sher、John M. Fevig、Andrew Alt、Robert L. Bertekap、Mary Jane Cullen、Timothy M. Harper、Kimberly Foster、Emily Luk、Qian Xiang、Mary F. Grubb、Jeffrey A. Robl、Dean A. Wacker
DOI:10.1021/acs.jmedchem.7b00385
日期:2017.7.27
additionally report the discovery and optimization of a novel class of nonbasic heterocyclic amide agonists of 5-HT2C. SAR investigations around the screening hits provided a diverse set of potentagonists at 5-HT2C with high selectivity over the related 5-HT2A and 5-HT2B receptor subtypes. Further optimization through replacement of the amide with a variety of five- and six-membered heterocycles led to the identification