A general and practicalmethod for the synthesis of 5-trifluoromethylpyrazoles is reported that occurs by the coupling of hydrazonyl chlorides with environmentally friendly and large-tonnage industrial feedstock 2-bromo-3,3,3-trifluoropropene (BTP). This exclusively regioselective [3 + 2] cycloaddition of nitrile imines and with BTP is catalyst-free and operationally simple and features mild conditions
A novel sequential [3+2] annulation reaction has been developed using prop-2-ynylsulfonium salts and hydrazonyl chlorides, affording a series of pyrazoles with functional motifs that can be post modified in the preparation of various drugs or drug candidates. Further transformation and gram-scale operations could also be achieved efficiently.
Synthesis and stereochemistry of some novel dihydropyrrolo[3,4-c]pyrazoles
作者:Yaşar Dürüst、Muhammet Yıldırım、Chris F. Fronczek、Frank R. Fronczek
DOI:10.1007/s00706-011-0618-z
日期:2012.1
AbstractEleven novel dihydropyrrolo[3,4-c]pyrazole derivatives were obtained by the reaction of chiral (1R)-N-(1-phenylethyl)maleimide and C,N-aryl-substituted nitrilimines. The reaction afforded the cycloadducts as a regioisomeric mixture which can be separable in some cases. The structure and stereochemistry of cycloadducts were assigned on the basis of infrared (IR), 1H and 13C nuclear magnetic
摘要通过手性(1 R)-N-(1-苯基乙基)马来酰亚胺与C,N-芳基取代的亚硝胺反应,制得了十一种新颖的二氢吡咯并[3,4- c ]吡唑衍生物。反应得到环加合物,为区域异构体混合物,其在某些情况下是可分离的。根据红外(IR),1 H和13 C核磁共振(NMR),质量和X射线光谱,旋光度测量和CHN分析确定环加合物的结构和立体化学。 图形概要 。
Synthesis, UV–Vis spectra, and Hammett correlation of some novel bis(dihydropyrrolo[3,4-c]pyrazoles)
作者:Yaşar Dürüst、Muhammet Yıldırım
DOI:10.1007/s00706-010-0351-z
日期:2010.9
AbstractTwenty-nine novel bis(dihydropyrrolo[3,4-c]pyrazole) derivatives were obtained by reacting C,N-phenyl-substituted nitrilimines generated in situ from corresponding hydrazonyl chlorides with bismaleimides. The structures were elucidated by physical and spectroscopic methods [m.p., R f, infrared (IR), 1H nuclear magnetic resonance (NMR), 13C NMR, correlation spectroscopy (COSY), heteronuclear
摘要通过使由相应的酰肼基氯化物就地生成的C,N-苯基取代的腈亚胺与双马来酰亚胺反应,获得了二十九种新型的双(二氢吡咯并[3,4- c ]吡唑)衍生物。通过物理和光谱方法[mp,R f,红外(IR),1 H核磁共振(NMR),13 C NMR,相关光谱(COSY),异核相关(HETCOR),核Overhauser效应(NOE)阐明了结构)和高分辨率质谱(HRMS)]。此外,哈米特常数之间获得哈米特相关图表σ p和λ 最大的双(pyrrolopyrazoles)值携带p取代的带苯基环的吸电子和供电子基团,并根据取代基效应进行讨论。 图形概要 。