在乙醇/ DMSO中,由α,β不饱和酮和水合肼与乙酸/甲酸合成了一系列2-吡唑啉。2-吡唑啉的结构已通过光谱技术确定,即UV,IR,1 H NMR,13 C NMR和微量元素分析。以固定的浓度和相同的激发波长在290 nm记录溶液中的荧光光谱。所有化合物的吸收带位置大致在280至336 nm之间,荧光带位置在300至370 nm(近紫外区域)之间。
Application of Fe3O4@SiO2@sulfamic acid magnetic nanoparticles as recyclable heterogeneous catalyst for the synthesis of imine and pyrazole derivatives in aqueous medium
作者:B. Zakerinasab、M. A. Nasseri、H. Hassani、M. M. Samieadel
DOI:10.1007/s11164-015-2204-1
日期:2016.4
Sulfamic acid supported on Fe3O4@SiO2 superpara magnetic nanoparticles was successfully applied as a recyclable solid acid catalyst with a large density of sulfamic acid groups for the synthesis of pyrazole derivatives, an important class of potentially bioactive compounds. The products are obtained in high yield from the one-pot reaction procedure involving dicarbonyl compounds and hydrazines/hydrazides. This new method totally avoids the use of toxic or expensive solvents and organic acids in this reaction.
PEG–SO3H as a mild, efficient and green catalytic system for the synthesis of pyrazole derivatives in aqueous medium
作者:M. A. Nasseri、S. A. Alavi、B. Zakeri Nasab
DOI:10.1007/s13738-012-0143-y
日期:2013.4
A versatile, alternative and environmentally benign strategy for the synthesis of a series of pyrazoles has been successfully performed in water using PEG–SO3H as an acidic catalyst. The products are obtained in high yield from the one-pot reaction procedure involving dicarbonyl compounds and hydrazines/hydrazides. This new method totally avoids the use of organic acids and toxic or expensive solvents in this reaction. The catalyst is waste-free, easily prepared, and efficiently re-used.
According to four different methods, various types of N-acylpyrazoles were prepared from the corresponding pyrazoles and carboxylic acids or their acid chlorides. Although N-acylpyrazoles were inert to alcohols under neutral or weakly basic conditions, the alcoholysis was dramatically accelerated by the action of strong acid or base. On the basis of these chemical properties, the regioselective synthesis of methyl benzyl 2,2-dimethylglutarate was achieved by selective protection and functionalization of a carboxylic acid derivative using N-acylpyrazoles.
Synthesis of [3,3′(4<i>H</i>,4′<i>H</i>)-Bi-2<i>H</i>-1,3-oxazine]-4,4′-diones and Their Hydrolysis
作者:Elif Korkusuz、İsmail Yıldırım
DOI:10.1002/hlca.201200463
日期:2013.7
The [3,3′(4H,4′H)‐bi‐2H‐1,3‐oxazine]‐4,4′‐diones 3a–3i were obtained by [2+4] cycloaddition reactions of furan‐2,3‐diones 1a–1c with aromatic aldazines 2a–2d (Scheme 1). So, new derivatives of bi‐2H‐1,3‐oxazines and their hydrolysis products, 3,5‐diaryl‐1H‐pyrazoles 4a–4c (Scheme 3), which are potential biologically active compounds, were synthesized for the first time.
Copper-catalyzed C–N cross-coupling of arylboronic acids with N-acylpyrazoles
作者:Jin Zhang、Run-Ping Jia、Dong-Hui Wang
DOI:10.1016/j.tetlet.2016.06.044
日期:2016.8
A copper-catalyzed C–N bond forming reaction of arylboronicacids and N-acylpyrazoles was developed. This procedure used N-acetyl protected pyrazoles as starting material instead of free pyrazoles (NH). The reaction worked under neutral conditions and did not require any base or ligand. The reaction showed good functional group tolerance.