Synthesis, Reactions and Characterization of 1,1’-(1,4-Phenylenebis(3-amino-6-methyl-1H-pyrazolo[3,4-b]pyridine-4,5-diyl))bis(ethan-1-one)

Reaction of 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-thioxo-1,2-dihydropyridine-3-carbonitrile) (1) with methyl iodide afforded the 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-(methylthio)nicotinonitrile) (2). The reaction of 2 with hydrazine hydrate followed by diazotization reaction af-forded the 1,1’-(1,4-phenylenebis(3-amino-6-methyl-1H-pyrazolo[3,4-b]pyridine-4,5-diyl))bis(e-than-1-one) (3) and 1,1’-(1,4-phenylenebis(3-(chlorodiazenyl)-6-methyl-1H-pyrazolo[3,4-b]-pyridine-4,5-diyl))bis(ethan-1-one) (4) respectively. On the other hand, reaction of 4 with malononitrile, 2-cyanoethanethioamide, ethyl acetoacetate, acetyl acetone, ethyl benzoylacetate, diethylmalonate, ethyl cyanoacetate and phenacylbromide aiming to build up pyrazolotriazine or pyrazole ring on the ring system of 4. Structures of all newly synthesized heterocyclic compounds in the present study were confirmed by considering the data of IR, 1H NMR, mass spectra as well as that of elemental analyses.

Catalyst free synthesis of fused pyrido[2,3-d]pyrimidines and pyrazolo[3,4-b]pyridines in water

A one-pot, three-component condensation reaction of an aldehyde, benzoyl acetonitrile （3-oxo-3-phenylpropane nitrile） and 6- amino-1,3-dimethylpyrimidine-2,4（1H,3H）-dione or 3-methyl-l-phenyl-lH-pyrazol-5-amine in water to give fused pyrido[2,3- d]pyrimidines and pyrazolo[3,4-b]pyridines in high yields without any catalyst, is described.

Pulmonary Edema and Pleural Effusion Detection Using Efficient Net-V1-B4 Architecture and AdamW Optimizer from Chest X-Rays Images

This paper presents a novelmulticlass systemdesigned to detect pleural effusion and pulmonary edema on chest Xray images,addressing the critical need for early detection in healthcare.A new comprehensive dataset was formed by combining 28,309 samples from the ChestX-ray14,PadChest,and CheXpert databases,with 10,287,6022,and 12,000 samples representing Pleural Effusion,Pulmonary Edema,and Normal cases,respectively.Consequently,the preprocessing step involves applying the Contrast Limited Adaptive Histogram Equalization(CLAHE)method to boost the local contrast of the X-ray samples,then resizing the images to 380×380 dimensions,followed by using the data augmentation technique.The classification task employs a deep learning model based on the EfficientNet-V1-B4 architecture and is trained using the AdamW optimizer.The proposed multiclass system achieved an accuracy(ACC)of 98.3%,recall of 98.3%,precision of 98.7%,and F1-score of 98.7%.Moreover,the robustness of the model was revealed by the Receiver Operating Characteristic(ROC)analysis,which demonstrated an Area Under the Curve(AUC)of 1.00 for edema and normal cases and 0.99 for effusion.The experimental results demonstrate the superiority of the proposedmulti-class system,which has the potential to assist clinicians in timely and accurate diagnosis,leading to improved patient outcomes.Notably,ablation-CAM visualization at the last convolutional layer portrayed further enhanced diagnostic capabilities with heat maps on X-ray images,which will aid clinicians in interpreting and localizing abnormalities more effectively.

Selective Synthesis of 1,2-Diarylpyrrolo[3,4-b]pyridine-5,7- diones via Cyclization Reaction of β-Enamino Imides with Cinnamaldehydes

The novel 1,2-diaryl substituted pyrrolo[3,4-b]pyridine-5,7-diones were selectively synthesized in high yields by the base catalyzed cyclization reaction of 3-arylamino-l-methyl-lH-pyrrole-2,5-diones with cinnamaldehyde and its derivatives in acetonitrile at room temperature. However, when piperidinium trifluoroacetate was employed as catalyst, the reaction afforded a mixture of 1,2-diaryl and 1,4-diaryl substituted pyrrolo[3,4-b]pyridine-5,7-diones in comparable yields.

Microwave-induced Stereoselectivity in Synthesis of trans-4-Aryl-3-methyl-6-oxo-4,5,6,7-tetrahydro-2H- pyrazolo[3,4-b]pyridine-5-carbonitriles

A facile synthesis of trans isomers of 4-aryl-3-methyl-6-oxo-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-b]pyridine-5- carbonitriles via three-component condensation reaction of an aldehyde, 3-amino-5-methylpyrazole and ethyl cyanoacetate in acetonitrile has been developed under microwave irradiation. This one-pot reaction proceeds with-out any catalyst in short times and gives the product in high selectivities and high yields.

Synthesis of Certain 3-Aminopyrazolo[5,4-b]pyridine and 3,4-Substituted Pyrido[2′,3′：3,4]pyrazolo[5,1-c][1,2,4]triazine Derivatives

2-Thioxo-1,2-dihydropyridine derivatives 2a, 2b were reacted with methyl iodide to give 2-methylthiopyridines 3a, 3b, which were reacted with hydrazine hydrate to produce 3-aminopyrazolo[5,4-b]pyridines 4a, 4b. Compounds 4a, 4b were diazotized to afford the corresponding diazonium salts 5a, 5b, which were reacted with some active methylene compounds 6a-6h to give the corresponding pyrido[2′,3′ ： 3,4]pyrazole[5,1-c][1,2,4]triazines 7-14.

Synthesis of derivatives of imidazo[4,5-b]pyridine:Novel sulfur contained side chains for macrolide antibiotics

Two series of novel derivatives of imidazo[4,5-b]pyridine were synthesized. These compounds could be used as side chains of semisynthesised ketolide antibiotics. The side chains have free amine group which can attached to ketolide core. Macrolides with this kind of side chains will show obvious activities against erythromycin-resistant strains. The structure of the side chains was confirmed by ^1H, ^13C NMR, MS, HMBC spectra. 2007 Ping Sheng Lei. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

A New Diiminopyridyl Cobalt Complex [CoCl_2L](L=2,6-Bis(N,N'-bis(2,6-diisopropyl-4-(2,3-dimethyoxylbenzoylamide)phenylimino))pyridine)

The reaction of CoCl2·6H2O with 2,6-bis（N,N＇-bis（2,6-diisopropyl-4-（2,3-dimethy-oxyl-benzoylamide）phenylimino））pyridine（L） afforded the complex [CoCl2L],which was fully characterized by elemental analysis,UV-vis,IR spectroscopy,fluorescence,and X-ray diffraction analysis.The compound is of triclinic system,space group P1 with a = 13.058（3）,b = 13.798（3）,c = 16.695（3） ,α = 98.191（3）,β = 102.792（3）,γ = 101.820（3）°,V = 2815.0（9） 3,Z = 2,F（000） = 1122,μ = 0.45 mm-1,R = 0.061 and wR = 0.1349 for 9842 observed reflections（Ⅰ 〉 2σ（Ⅰ））.The Co（Ⅱ） center adopts a distorted square-pyramidal coordination geometry.The extended structure shows a one-dimensional zigzag double chain linked by hydrogen bonds and π-π stacking interactions.

New and Facile Synthesis of Substituted Pyrrole, Pyridine, Pyrazolo[4,3-b] Pyridine, Pyrano[3,2-c] Quinoline, Napthopyran, Naphthodipyran and Coumarin Derivatives

Several new pyrazolo[4,3-b] pyridines 7a, b were prepared by reacting arylidenemalononitriles 1a, c or 1i, j with 4-nitrosoantipyrine 4. Reacting 1a, b, d with 4-azidomethylcarbonylantipyrine 8 give 2-aminopyrrole 14. Pyrano[3,2-c] quinolines 20a, b and 23 were obtained by reacting 4-hydroxyquinoline 15 with 1g, h, 2b respectively. Reaction of 1 with naphthalenediols 24, 27 and 29 yield naphthodipyrans 26a, b, 28a, b and 30a。

Theoretical Study on the Reaction Mechanism of 2-Methoxybenzaldehyde,4-Bromo-indanone,Malononitrile and Ammonium Acetate One-pot to Form 6-(2-Methoxyphenyl)-2-amino-6-bromo-5H-indeno[1,2-b]pyridine-3-carbonitrile

The reaction mechanism of 2-methoxybenzaldehyde, 4-bromo-indanone, malononitrile and ammonium acetate one-pot to form 6-（2-methoxyphenyl）-2-amino-6-bromo-5 Hindeno[1,2-b]pyridine-3-carbonitrile was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Reaction pathways were investigated in this study. The result indicates that the reaction Re→ TSB1→IMB1→ TSB2→ IMB2→TSB3→IMB3→TSB4→IMB4→TSB5→IMB5→TSB6→IMB6→TSB7→IMB7→ TSB8→IMB8→TSB9→IMB9→P2 is the main pathway, the activation energy of which is the lowest. The dominant product predicted theoretically is in agreement with the experiment results.

Crystal Structure of Poly[(2,6-di(2’,4’-dicarboxylphenyl)pyridine-κ4 O:O′:O″:O′′′)-(μ2-1,4-bis(1-imidazolyl)benzene-κ2N:N’)cobalt(II)],C_(39)H_(24)Co_(2)N_(7)O_(8)

[Objective]The paper was to synthesize a new structure of metal organic framework,and to provide new materials for plant pathogens testing.[Method]A mixture of 2,6-di(2’,4’-di-carboxylphenyl)pyridine,1,4-bis(1-imidazolyl)benzene,Co(NO_(3))2·6H_(2)O were added to the solution of DMF:H2O=3:3 and heated at 433K for 4 d.[Result]Red crystals of the title compound were obtained(yield 76.3%,based on Co).[Conclusion]The crystal data were obtained as follows:C_(39)H_(24)Co_(2)N_(7)O_(8),monoclinic,P21/c,a=16.222(7)A,b=12.653(5)A,c=17.456(7)A,β=102.386(6)°,V=3500(2)A_(3),Z=4,Rgt(F)=0.0550,wRref(F2)=0.1509,T=293(2)K.

Synthesis and Crystal Structure of 4-(2- Chlorophenyl)-5-cyano-3-methyl-6-oxo-1- phenyl-4,5,6,7-tetrahydropyrazolo[3,4-b] Pyridine under Microwave Irradiation

The title compound (C20H15ClN4O, Mr = 362.81) was synthesized by the reaction of ethyl 2-cyano-3-(2-chlorophenyl)-1-acylate with 5-amino-3-methyl-1-phenylpyrazole under microwave irradiation and its structure was determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n with a = 8.8192(19), b = 15.976(3), c = 13.094(3) ? = 103.074(4), V = 1797.1(7) ?, Z = 4, Dc = 1.341 g/cm3, = 0.229 mm-1, F(000) = 752, R = 0.0632 and wR = 0.1278. X-ray analysis reveals that the pyridine ring adopts an envelope conformation. The dihedral angle between the pyrazole and pyridine planes is 2.19, and inter- molecular hydrogen bonds are also observed in the molecule.

黄芩素抑制Toll样受体4/核因子-B炎症通路改善小鼠脑出血后脑损伤的作用及机制研究

目的 探讨黄芩素抑制Toll样受体4(TLR4)/核因子-κB(NF-κB)炎症通路改善小鼠脑出血后脑损伤的作用及机制研究。方法 通过胶原酶注射小鼠右侧基底节区诱导小鼠脑出血,模型模型诱导后小鼠腹腔注射不同剂量黄芩素或者同体积溶剂,并通过神经功能学评分及脑水含量分析其保护作用;通过不同时间点给药(模型诱导后6及12h),评估黄芩素治疗时间窗;对TLR4和NF-κB信号通路的变化、小胶质细胞活化及神经细胞退变(FJC)进行检测。结果 黄芩素可减轻脑出血后脑水含量并改善神经功能学评分,并且模型诱导后6 h开始治疗,仍然有效;黄芩素可减少脑出血后神经细胞变性;黄芩素通过抑制小胶质细胞活化及TLR4/NF-κB通路及其下游促炎因子(TNF-α及IL-1β)的产生发挥抗炎作用。结论 黄芩素在脑出血后通过抗细胞死亡和抗炎作用发挥神经保护作用。

Studies on the Synthesis of Pyridine Analogs of the Natural Product3,5,4'-Trimethoxystilbene

Five pyridine analogs of the natural product, 3, 5, 4'-trimethoxystilbene, were synthesized. The final compounds were characterized by 1H-NMR.

佛手多糖对1-甲基-4-苯基-吡啶离子诱导人神经母细胞瘤(SH-SY5Y)细胞损伤的保护作用研究

该文探究佛手多糖对1-甲基-4-苯基-吡啶离子(1-methyl-4-phenyl-pyridine ion,MPP+)诱导人神经母细胞瘤(SH-SY5Y)细胞损伤的保护作用及其机制。佛手多糖经大孔吸附树脂AB-8进行纯化。体外培养SH-SY5Y细胞,构建帕金森病(Parkinson′s disease,PD)细胞模型,实验分为对照组、MPP+模型组、佛手多糖组。采用噻唑蓝(methye thiazdye telrazlium,MTT)法检测细胞存活率,Hoechst33258染色法观察细胞形态,2′,7′-二氯荧光黄双乙酸盐荧光探针检测细胞活性氧(reactive oxygen species,ROS)水平,JC-1荧光探针法检测线粒体膜电位,蛋白免疫印迹(Western blot)检测磷酸化蛋白激酶B(phosphorylated protein kinase B,p-Akt)、蛋白激酶B(protein kinase B,Akt)、磷酸化细胞外调节蛋白激酶(phosphorylated extracellular regulated protein kinases1/2,p-ERK1/2)和细胞色素c(cytochrome c,Cyt-c)蛋白表达水平。结果表明,佛手多糖的得率4.86%,纯度为44.46%,经过AB-8纯化后,纯度提高到60.81%;与对照组相比,模型组细胞的存活率显著降低,Hoechst33258染色下可见细胞破碎,细胞核皱缩,细胞内ROS显著增加,线粒体膜电位显著降低。与模型组相比,佛手多糖组的细胞存活率显著增加,细胞形态明显得到改善,ROS水平下降,线粒体膜电位升高。Western blot结果显示,佛手多糖能抑制MPP+引起的p-Akt和p-ERK1/2的降低,以及Cyt-c的上升。综上,佛手多糖对MPP+诱导SH-SY5Y细胞损伤具有保护作用,其机制可能是通过调节线粒体ROS的产生和Cyt-c的释放,进而维持线粒体稳态,激活Akt信号通路和ERK信号通路,抑制细胞的凋亡,从而起到保护作用。研究结果可为缓解帕金森病的发生发展提供理论依据,同时也能更好地开发和利用佛手资源。

Synthesis,Crystal Structure,DFT Studies and Biological Activity of a Novel Schiff Base Containing Triazolo[4,3-a]pyridine Moiety

The novel Schiff base（E）-8-chloro-NA-（4-（dimethylamino）benzylidene）-[1,2,4]triazolo[4,3-a]pyridine-3-carbohydrazide was synthesized and characterized by ^1H NMR,MS,elemental analysis and X-ray diffraction.The compound crystallizes in the monoclinic space group P2_1/c with a = 7.091（2）,b = 10.750（3）,c = 21.380（6） A,β = 96.299（6）°,V = 1619.7（8） A^3,Z = 4 and R = 0.0351.Theoretical calculation of the title compound was carried out with the B3LYP/6-31 G basis set.The frontier orbital energy and atomic net charges were discussed.It is found that the experimental data show good agreement with the calculated values.And the compound exhibits good antifungal activity against Stemphylium lycopersici（Enjoji） Yamamoto.

A New Zn(Ⅱ) Coordination Polymer Constructed from 4-(1H-pyrazol-3-yl)pyridine as Fluorescent Sensor for Fe^(3+)

A new Zn(Ⅱ) coordination polymer, [Zn(4-PP)(1,4-BDC)?(H_2O)]_n(1, 4-PP = 4-(1 H-pyrazol-3-yl)pyridine, 1,4-H_2BDC = 1,4-benzenedicarboxylic acid), has been synthesized and structurally characterized by single-crystal X-ray diffraction as well as elemental analysis, IR spectra, XRPD and TG. Structural analysis reveals that Zn(Ⅱ) ions are bridged by COO-from 1,4-BDC^(2-)to form a binuclear structure as the second building units(SBUs). Zn_2 clusters can be clarified as 4-connected nodes, so the framework of 1 can be considered as a 2 D(44?62)-sql sheet. Fluorescence measurements show that 1 has highly selective and sensitive detection of Fe^(3+) in water medium.

Synthesis,Crystal Structure and Antifungal Activity of 8-Chloro-3-((4-chlorobenzyl)-thio)[1,2,4]triazolo[4,3-a]pyridine

The title compound 8-chloro-3-（（4-chlorobenzyl）thio）-[1,2,4]triazolo[4,3-a]pyridine was prepared from 1-chloro-4-（chloromethyl）benzene and 8-chloro-[1,2,4]triazolo[4,3-a]pyridine-3（2H）-thione in the presence of Na OH, and its structure was determined by X-ray diffraction analysis. The crystal is of triclinic system, space group P1 with a = 6.8264（6）, b = 7.5890（4）, c = 13.0960（7） A, α = 93.447（4）, β = 98.772（6）, γ = 92.615（6）o, V = 668.26（8） A3, Z = 2, the final R = 0.035 and wR = 0.09 for 2259 observed reflections with I 〉 2σ（I）. The preliminary biological test showed that the title compound has activities against Stemphylium lycopersici（Enjoji） Yamamoto, Fusarium oxysporum. sp. cucumebrium, and Botrytis cinerea with inhibitory to be 51.19%, 62.02% and 15.56%, respectively.