885319-49-3Relevant articles and documents
Highly regioselective organocatalyzed synthesis of pyrazoles from diazoacetates and carbonyl compounds
Wang, Lei,Huang, Jiayao,Gong, Xiaojie,Wang, Jian
supporting information, p. 7555 - 7560 (2013/07/05)
A general, organocatalytic inverse-electron-demand [3+2] cycloaddition reaction between a range of carbonyl compounds and diazoacetates has been developed. This reaction is catalyzed by secondary amines as a "green promoter" to generate substituted pyrazoles with high levels of regioselectivity. It is noteworthy that this [3+2] cycloaddition reaction proceeds efficiently at room temperature with a simple and inexpensive catalyst. Considering the large variety and ready availability of the starting materials (e.g. ketones, β-ketoesters, β-diketones, and aldehydes), as well as the operational simplicity of this process, a convenient, practical, and highly modular pyrazole synthesis has been developed. We believe that this work will arouse more research interest in the organocatalytic synthesis of other biologically active heterocycles. Such studies are currently underway in our laboratory. Dipoles apart: In situ formed enamines react with diazoacetates under mild conditions to afford the corresponding polysubstituted pyrazoles in good-to-excellent yields through an inverse-electron-demand 1,3-dipolar cycloaddition process (see scheme). Copyright
Fluorinated pyrazole acids are agonists of the high affinity niacin receptor GPR109a
Skinner, Philip J.,Cherrier, Martin C.,Webb, Peter J.,Shin, Young-Jun,Gharbaoui, Tawfik,Lindstrom, Andrew,Hong, Vu,Tamura, Susan Y.,Dang, Huong T.,Pride, Cameron C.,Chen, Ruoping,Richman, Jeremy G.,Connolly, Daniel T.,Semple, Graeme
, p. 5620 - 5623 (2008/04/02)
A series of 5-alkyl pyrazole-3-carboxylic acids were prepared and found to act as potent and selective agonists of the human GPCR, GPR109a, the high affinity nicotinic acid receptor. No activity was observed at the highly homologous low affinity niacin receptor, GPR109b. A further series of 4-fluoro-5-alkyl pyrazole-3-carboxylic acids were shown to display similar potency. One example from the series was shown to have improved properties in vivo compared to niacin.
