An efficient regioselective sonochemical synthesis of novel 4-aryl-3-methyl-4,5-dihydro-1H-pyrazolo[3,4-b]pyridin-6(7H)-ones

An efficient ultrasound-assisted preparation of a series of novel 4-aryl-3-methyl-4,5-dihydro-l//-pyrazolo[34-b]pyridin-6(7H)ones via the reaction of 5-amino-3-methyl-1H-pyrazole,Meldrum’s acid and various arylaldehydes using one-pot three-component approach is described.This rapid method produced the products in short reaction times(3-4 min) and excellent yields(87-95%).     

3-氨基-6/8取代-1H-吡唑[4,3-c]喹啉类化合物的合成

研究了合成3-氨基-6/8取代-1H-吡唑[4,3-c]喹啉类化合物的简易方法.通过3-芳基-4-氨基-5-巯基-1,2,4-三唑与6-/8-取代-4-羟基喹啉羧酸在三氯氧磷催化下的缩合反应及所生成的3-芳基-6-(6-/8-取代-4-氯喹啉-3-基)-1,2,4-三唑[3,4-b]-1,3,4-噻二唑类化合物与水合肼在乙醇中的肼解反应,合成了6个3-氨基-6/8取代-1H-吡唑[4,3-c]喹啉类化合物,并对活泼的氨基进行了初步研究,新化合物通过元素分析,IR,¹HNMR和MS确定结构,并讨论了其波谱性质.     

Synthesis of 1,3-Bis[(3-aryl)-S-triazolo[3,4-b]-[1,3,4]thiadiazole-6-yl]benzenes

1,3-bis[(3-aryl)-s-triazolo[3,4-b]-[1,3,4]thiadiazole-6-yl]benzenes 2 were synthesized in high yields by the reaction of 3-aryl 4-amino-5-mercapto-1,2,4-triazole 1 with m-phthalic acid.     

5-氨基-6-硝基-[1,2,5]噁二唑并[3,4-b]吡啶-1-氧化物的合成新方法

以2,6-二氯吡啶为起始原料, 经肼基化、还原、硝化、Nietzki-Dietschy环合4步反应得到5-氨基-6-硝基-[1,2,5]噁二唑并[3,4-b]吡啶-1-氧化物。 结合反应机理讨论了还原、硝化、Nietzki-Dietschy环合反应的影响因素,获得了合成5-氨基-6-硝基-[1,2,5]噁二唑并[3,4-b]吡啶-1-氧化物的最佳工艺条件,目标产物的总收率为59.2%。 用1H NMR、MS和IR谱对5-氨基-6-硝基-[1,2,5]噁二唑并[3,4-b]吡啶-1-氧化物的结构进行了表征。     

The Synthesis and Fungicidal Activities of 2,6-Bis[(3-aryl)-s-triazolo[3,4-b]-[1,3,4]thiadiazole-6-yl]pyridines

In search of better bioactive compounds, a series of novel 2,6-bis[(3-aryl)-s-triazolo[3,4-b]-[1,3,4]thiadiazole-6-yl]pyridines 2 were synthesized in high yields by the cyclization of 3-aryl-4-amino-5-mercapto-1, 2, 4-triazoles 1 with 2,6-pyridine dicarboxylic acid. 2 exhibited good fungicidal activities against Cerospora beticola sacc.     

1H-Pyrazolo[3,4-b]pyridines: Synthesis and Biomedical Applications

Pyrazolo[3,4-b]pyridines are a group of heterocyclic compounds presenting two possible tautomeric forms: the 1H- and 2H-isomers. More than 300,000 1H-pyrazolo[3,4-b]pyridines have been described which are included in more than 5500 references (2400 patents) up to date. This review will cover the analysis of the diversity of the substituents present at positions N1, C3, C4, C5, and C6, the synthetic methods used for their synthesis, starting from both a preformed pyrazole or pyridine, and the biomedical applications of such compounds.     

Preparation and Spectral Characterization of 3-Benzyl-6-aryl-1,2,4-triazolo[3,4-b][1,3,4]thiadiazoles

3-Benzyl-4-amino-5-mercapto-1,2,4-triazole reacted with aromatic acids in the presence of phosphorus oxychloride, yielding a series of new compounds, i.e., 3-benzyl-6-aryl-1,2,4-triazolo[3,4-b][1,3,4]thiadiazoles, each of which has an active methylene at 3-position. The structures of all the title compounds were confirmed by elementary analysis, IR, 1H NMR and 13C NMR spectra.     

Preparation and Electrochemical Properties of 3-Phenyl-6-aryl-1,2,4-triazolo[3,4-b][1,3,4]-thiadiazoles

Introduction Since Tang[1] firstly reported the electroluminescence of 8-hydroxyquinoline aluminium, much attention has been paid to the organic compound as electro-luminescent material. Especially, electron transport materials play an important role in organic light-emitting diode(OLED). 2-(4-Biphenyl)-5-(t-butylphenyl)-1,3,4-oxadiazole(PBD), as a kind of popular electron injection/transport materials, can improve remarkably the injection balance of electrons and holes. As a result, it can amend the properties of OLED[2,3].     

Synthesis of 3-amino-4-methyl-6-trifluoromethylthieno[2,3-b]pyridine-2-carboxanilide and its crystal and molecular structure

4-Methoxy-1,1,1-trifluoropent-3-en-2-one reacts with cyanothioacetamide to give 3-cyano-4-methyl-6-trifluoromethylpyridine-2(1H)-thione, which was transformed into 3-amino-4-methyl-6-trifluoromethylthieno[2,3-b]pyridine-2-carboxanilide by the reaction with chloroacetanilide. The crystal and molecular structure of the amide obtained was studied by X-ray analysis. Translated fromIzvestiya Akademii Nauk Seriya Khimicheskaya, No. 4, pp. 701–703, April, 1998.     

Preparation and Electrochemical Properties of 3-Phenyl-6-aryl-1,2,4-triazolo[3,4-b][1,3,4]-thiadiazoles

Since Tang firstly reported the electroluminescence of 8-hydroxyquinoline aluminium, much attention has been paid to the organic compound as electro-luminescent material. Especially, electron transport materials play an important role in organic light-emitting diode (OLED).2-(4-Biphenyl)-5-(t-butylphenyl)-1, 3,4-oxadiazole (PBD), as a kind of popular electron injection/transport materials, can improve remarkably the     

Synthesis of 3-acetyl-4-amino-6-arylpyran-2-ones and ethyl 7-aryl-4,5(1H,5H )-dioxopyrano[4,3-b]pyridine-2-carboxylates

The reactions of aroylacetonitriles with the nickel chelate of ethyl acetoacetate afforded new block heterocyclic reagents, viz., 3-acetyl-4-amino-6-arylpyran-2-ones. The reactions of the latter with diethyl oxalate gave rise to ethyl 7-aryl-4,5(1H,5H)-dioxopyrano[4,3-b]pyridine-2-carboxylates.     

三组分一锅法合成1-羧甲基-6-芳基-1,2,3,4,5,6-六氢茚并[2,3-b]-喹啉-5,11-二酮

以芳醛、1,3-茚二酮、烯胺酮为原料, 冰醋酸为溶剂, 三组分一锅法合成了一系列茚并[2,3-b]喹啉类化合物. 该反应产率高(83%～93%)、操作简单、后处理方便. 产物的结构通过红外光谱、核磁共振谱和元素分析证实, 同时给出了该反应可能的反应机理.     

Preparation and Electrochemical Properties of 3-Pyridinyl-6-aryl-1, 2, 4-triazolo [3, 4-b][1, 3, 4]thiadiazoles

A series of 3-pyridinyl-6-aryl-1, 2, 4-triazolo[3, 4-b][1, 3, 4]thiadiazoles(PATT) were prepared, the structures were confirmed by 1R and ^1H NMR spectra. The results of cyclic voltammetry measurements imply that all these compounds have a higher electron affinity (EA) than 2-(4-biphenyl)-5-(4-tert-butyl phenyl)-1, 3. 4-oxadiazole (PBD) which implies that PATT could be acting as better electron acceptors than widely used electron transporting material PBD.     

Pyridazine Derivatives and Related Compounds,Part 221: Synthesis,Reactions, and Insecticidal Activity of 3-Amino-5,6-diaryl-1H-pyrazolo[3,4-c]pyridazines

Starting with 3-amino-5,6-diaryl-1H-pyrazolo[3,4-c]pyridazine, the syntheses of thiourea derivatives, dithiocarbamates, ethyl carbamate, phosphoranylidene amino, and substituted acetamido derivatives are described. The products were screened for their insecticidal activity against Mucsa, domestica, and Aphid, Macrosiphum pisi.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

1H-Pyrazolo[3,4-b]quinolines: Synthesis and Properties over 100 Years of Research

This paper summarises a little over 100 years of research on the synthesis and the photophysical and biological properties of 1H-pyrazolo[3,4-b]quinolines that was published in the years 1911–2021. The main methods of synthesis are described, which include Friedländer condensation, synthesis from anthranilic acid derivatives, multicomponent synthesis and others. The use of this class of compounds as potential fluorescent sensors and biologically active compounds is shown. This review intends to summarize the abovementioned aspects of 1H-pyrazolo[3,4-b]quinoline chemistry. Some of the results that are presented in this publication come from the laboratories of the authors of this review.     

6-氨基-5-氰基-3-甲基-4-(3-硝基苯)-1-苯基吡唑[3,4-b]并吡啶与人血清白蛋白结合作用的光谱特征

采用紫外光谱法和荧光光谱法研究了6-氨基-5-氰基-3-甲基-4-(3-硝基苯)-1-苯基吡唑[3,4-b]并吡啶(6A)与人血清白蛋白(HSA)的结合作用,利用同步荧光法和三维荧光法研究了6A与HSA作用前后人血清白蛋白的构象变化。观测到生理pH7.4条件下6A使HSA的紫外吸收峰增强,特征荧光峰猝灭。Stern-Volmer曲线显示,6A对HSA的荧光猝灭可能是一个单一的静态猝灭过程,并且得出18℃和37℃时的结合位点数和结合常数。根据F rster非辐射转移理论可求出6A与HSA作用距离r=3.73 nm;根据基本热力学参数ΔH、ΔS和ΔG判断6A和HSA主要通过氢键和范德华力发生相互作用。     

Synthesis of Some New Pyrazolo[3,4-b]Pyridlne and Pyrazolo[3,4-d]Pyrimidine Derivatives1

Several pyrazolo[3,4-b]pyridine (3,4) and pyrazolo-[3,4-d]pyrimidine (5-13) derivatives were prepared using 5-amino-l-(5-ethyl-5H-1,2,4-triazino[5,6-b]-indol-3-yl)-lH-pyrazole-4-carbonitrile (2) . The pyridine derivatives 3 and 4 were obtained by reaction of 2 with malononitrile and ethyl cyanoacetate, respectively, while pyrimidine analogs 5-13 were synthesized cither by a one-step or multi-step sequence.     

3-(2-氟-4-氯-5-取代基苯基)-7-甲基-3H-吡唑并[3,4-d][1,2,3]三嗪- 4(7H)-酮化合物的合成及其对原卟啉原氧化酶的抑制活性

为了发现新型的原卟啉原氧化酶抑制剂, 根据生物合理设计方法, 设计并合成了一系列的结构新颖的3H-吡唑并[3,4-d][1,2,3]三嗪-4-酮衍生物. 利用不同取代的5-氨基-吡唑-4-甲酰氯与取代苯胺反应制得的5-氨基-N-苯基-1H-吡 唑-4-甲酰胺衍生物, 经进一步重氮化得到目标化合物, 并对化合物3f进行衍生化. 所得目标化合物的结构均经1H NMR, IR和元素分析确证. 生物活性测定结果表明, 部分化合物对原卟啉原氧化酶有较高的抑制活性, 讨论了其结构与活性的关系.     

微波辐射下2-氨基-7-甲基-4-芳基-5-氧代-4H,5H-吡喃并[4,3-b]吡喃-3-腈的一步合成

芳醛、丙二腈与6-甲基-4-羟基-2-吡喃酮在微波辐射下, 一步反应得到一系列2-氨基-7-甲基-4-芳基-5-氧代-4H,5H-吡喃并[4,3-b]吡喃-3-腈, 该反应时间短、产率较高、环境友好、后处理简单. 产物的结构经红外光谱、核磁共振谱和元素分析表征, 产物4g的结构经单晶X射线衍射进一步确证; 并对反应过程提出了可能的机理.