Synthesis and in vitro-Anti-hepatitis B Virus Activities of Several Ethyl 5-Hydroxy-1H-indole-3-carboxylates

A series of ethyl 5-hydroxyindole-3-earboxylates 6a-10r was designed and synthesized. The structures of all the compounds were confirmed by IR, ^1H NMR, and MS and their anti-hepatitis B virus （HBV） activities were evaluated in 2.2.15 cells. Among them, compound 7g { ethyl 5-hydroxy-2- [ （ 3-methoxyphenylsulfinyl ） methyl ] -1-methyl-4- [ （4-methylpiperazin-1-yl） methyl ]-1H-indole-3-carboxylate} displays a significant anti-HBV activity, which is more potent than the positive control lamivudine.

Synthesis and in vitro Anti-hepatitis B Virus Activity of Some Ethyl 5-Hydroxy-4-substituted Aminomethyl-2-sulfinylmethyl-1H-indole-3-carboxylates

A novel series of ethyl 5-hydroxy-4-substituted aminomethyl-2-sulfinylmethyl-lH-indole-3-carboxylates 8a--8j and 11e--11f was synthesized and evaluated in HepG2.2.15 cells for their anti-hepatitits B virus（HBV） activity and cytotoxicity. Among them, six compounds showed more potent inhibitory activity than lamivudine. Compound 8e exhibited the most significant anti-HBV activity with an IC50 value of 1.62 μmol/L, which was 33-times more potent than the reference drug lamivudine（IC50=54.78μmol/L）.

Green Chemistry Approach to Fast and Highly Efficient One-Pot Synthesis of Bis-Isoxazolyl-1,2,5,6-Tetrahydro Pyridine-3-Carboxylates

The synthesis of the bis-isoxazolyl-1,2,5,6-tetrahydro pyridine-3-carboxylates is achieved in high yield without the production of toxic waste products by using room temperature ionic liquid (RTILs) triethyl ammonium acetate (TEAA). The RTIL TEAA played the dual role of efficient green solvent as well as recyclable catalyst.

A new and efficient method for the synthesis of isoquinoline-3-carboxylate

An isoquinoline-3-carboxylate compound 3 was obtained with a moderate yield of 40% when N-acetyl-（3′-hydroxy-4′- methoxy-5′-methyl）phenylalanine methyl ester 1 was refluxed in HMTA/TFA. However, the anticipated product N-acetyl-（3′- hydroxy-4′-methoxy-5′-methyl-6′-formyl）phenylalanine methyl ester 2 could not be found. The possible mechanism was discussed in this article.

Synthesis and Crystal Structure of a Novel Ethyl 5-(4-(2-Phenylacetamido)phenyl)-1H-pyrazole-3-carboxylate as an Acrosin Inhibitor

The title compound （ethyl5-（4-（2-phenylacetamido）phenyl）-lH-pyrazole-3-carboxylate, C20H19N3O3） was synthesized by the reaction of Claisen condensation, cyclization, reduction and acylation. The structure was characterized by X-ray diffraction, MS, NMR and IR. It belongs to the monoclinic system, space group C2/c with a = 22.723（9）, b = 9.324（4）, c = 18.890（8） A, β = 114.259（6）°, V = 3649（3） A^3, Dc = 1.272 Mg·m^3, Z = 8, Mr = 349.38, p = 0.087 mm^-1, F（000） = 1472, the final R = 0.0615 and wR = 0.1643. The biological test shows that the title compound has a moderate acrosin inhibition activity.

Raman Spectra of 1,2,4-Triazole-3-carboxylate Solution

Raman spectra of 1,2,4-triazole-3-carboxylate (TC- anion) and its ring-deprotonated deriva- tive (dpTC2- dianion) in aqueous solutions were measured respectively. The density func- tional theory calculations were performed using MN15 functional and PCM solvent model to investigate their structures, as well as the vibrational frequencies and Raman intensi- ties. With the aid of the calculated spectra, all the observed Raman bands of dpTC2- were clearly assigned, with taking into account the deuteration shifts. Moreover, various protonic tautomers of TC- anion were compared in the present theoretical calculations, and 2H- tautomer was found more stable. The experimental Raman spectrum of TC- solution was roughly consistent with the calculated spectrum of the monomeric 2H-tautomer of TC-, but some splits existed for a few bands when compared to the calculated spectra, which might be contributed by the hydrogen-bonding dimers of TC-.

Synthesis and Anti-influenza Virus Activity of Ethyl 6-Bromo-5-hydroxyindole-3-carboxylate Derivatives

A series of ethyl 6-bromo-5-hydroxyindole-3-carboxylate derivatives were synthesized and their in vitro anti-influenza virus activity was evaluated. All the compounds were characterized by 1H NMR and MS.

Syntheses and Characterization of Two New Alkaline Earth Metal-organic Topological Frameworks with 3-Amino-1H-1,2,4-triazole-5-carboxylate

Two new alkaline earth metal coordination polymers constructed from the deriva-tive of 1,2,4-triazole are presented herein,namely,{[Sr（AmTAZAc）2（H2O）]}（1） and {[Ba（AmTAZAc）2（H2O）]}（2）（AmTAZAc = 3-amino-1H-1,2,4-triazole-5-carboxylate）,which have been synthesized by using the layering method and structurally characterized by elemental analysis,IR,and single-crystal X-ray diffraction.Complexes 1 and 2 are isostructural,and both crystallize in the orthorhombic system,space group Fdd2.X-ray structural analysis shows that 1 or 2 has an intriguing 3-D infinite network of（318.438.510） topology based on a 2-D sheet structure of（4,4） net.The result shows that noncovalent interactions play an important role in strengthening the whole structures of the compounds.

Synthesis, Spectral and Electrochemical Studies of Complex of Uranium(IV) with Pyridine-3-Carboxylic Acid

The investigation of complexation of uranium with biological active ligands is vital for understanding uranium speciation in biosystems. A number of studies have been undertaken for investigating the complexation of uranium in its (VI) oxidation states but similar investigations pertaining to the interaction of uranium, in lower oxidation states, with biological ligands is scarce. The aim of the work is to bridge this gap and studies have been carried out to determine the coordination pattern of pyridine-3-carboxylic acid with uranium(IV). Semi-micro analysis, spectro-analytical techniques, magnetic susceptibility and cyclic voltammetry have been employed for the characterization of the synthesized complex.

Synthesis and Crystal Structure of Methyl 2-(Diphenylamino)-4-phenyl-1,3-thiazole-5-carboxylate

The title compound, methyl 2-（diphenylamino）-4-phenyl-1,3-thiazole-5-carboxylate, was synthesized and studied by single-crystal X-ray diffraction method. The structure of the product was confirmed by IR, 1H- and 13C-NMR spectroscopy and elemental analysis. These experimental studies were supported by quantum mechanical calculations. The structure was solved in monoclinic, space group P21/c with a = 9.573（3）, b = 19.533（7）, c = 9.876（3）, β = 92.35（4）°, V = 1845.2（10）3, T = 85（2） K, Z = 4, R = 0.040 and wR = 0.089 for 6424 observed reflections with I2σ（I）.

Synthesis of (2S,4S)-2-Substituted-3- (3-Sulfanylpropanoyl)-6- Oxohexahydropyrimidine-4-Carboxylic Acids as Potential Antihypertensive Drugs

Proceeding from natural amino acid L-asparagine and commercially available aldehydes a stereoselective synthesis was developed of (2S,4S)-2-alkyl(aryl)-3-(3-sulfanylpropanoyl)-6-oxohexahy- dropyrimidine-4-carboxylic acids, potential antihypertensive drugs, inhibitors of the angiotensin converting enzyme.

吡唑化合物pyr3干预对压力负荷诱导的大鼠左心室肥厚的影响

目的：探讨瞬时受体电位通道C亚族3亚型（TRPC3）的选择性阻滞剂吡唑化合物Ethyl-1-（4-f2，3，3一trichloroacrylamide）phenyl）-5-（trifluoromethyl）-1H—pyrazole-4-carboxylate（pyr3）的体内干预对压力负荷大鼠左心室肥厚（LvH）程度的影响。方法：采用腹主动脉缩窄手术建立左心压力负荷模型。30只200—240g雄性SD大鼠随机分为五组（n=6）：假手术对照组、手术对照组、假手术后全程给药组、手术后后期给药组，手术后全程给药组。6周后，计算各组大鼠左心室质量指数、左心室心肌细胞横径，逆转录多聚酶连反应（RT—PCR）、免疫组织化学和蛋白免疫印迹检测TRPC3和钙调神经磷酸酶A13信使核糖核酸（mRNA）和蛋白的表达水平。结果：与假手术对照组相比，手术对照组左心室肥厚相关指标（左心室质量指数和左心室心肌细胞横径）及TRPC3、钙调神经磷酸酶AB蛋白和mRNA的表达显著升高；假手术后全程给药组左心室肥厚相关指标无显著变化，而TRPC3和钙调神经磷酸酶AB蛋白及mRNA的表达量显著升高，差异均有统计学意义（P均〈0．05）。与手术对照组比较，手术后全程给药组左心室肥厚相关指标、TRPC3及钙调神经磷酸酶A13蛋白和mRNA表达均明显降低（P均〈0．05）；手术后后期给药组左心室肥厚相关指标及钙调神经磷酸酶AB蛋白和mRNA的表达下降，差异均有统计学意义（P均〈0．05），而TRPC3的蛋白和mRNA表达未见显著降低。结论：pyr3体内干预能够一定程度上阻止压力负荷导致的大鼠左心室肥厚，降低压力负荷大鼠左心室TRPC3和钙调神经磷酸酶AB表达的上调。

Structure and Luminescent Property of a Novel 4-Hydroxyquinoline-2-carboxylate Based Zn(Ⅱ) Complex

A 3D coordination polymer [Zn2（hqc）2（H2O）]n has been obtained from the reaction of 4-hydroxyquinoline-2-carboxylic acid （H2hqc） with zinc（II） salt under hydrothermal condition, and characterized by elemental analysis, IR, TGA, PXRD and X-ray single-crystal diffraction. The complex crystallizes in the monoclinic system, space group P21/c with a = 14.305（2）, b = 9.132（2）, c = 15.356（2）, β = 103.586（7）o, V = 1949.9（4）3, Z = 4, Dc = 1.782 g/cm3, μ = 2.508 mm-1, Mr = 523.06, F（000） = 1048, T = 293（2） K, λ（MoKα） = 0.71073, S = 1.008, the final R = 0.0329 and wR = 0.0745 for 3849 observed reflections （I 〉 2σ（I））. The title complex features a 3D framework via Zn（2） linking the 1D {Zn1（hqc）2}n chains. Thermogravimetric analysis shows that its framework is highly thermally stable up to 556 ℃ in the solid state.

Synthesis and Crystal Structure of a One-dimensional Infinite Chain Organotin Complex [(n-Bu)_3Sn(OCOC_5H_4NO)]_n

A novel organotin complex [（n-Bu）3Sn（OCOC5H4NO）]n has been synthesized and characterized by elemental analysis, IR and ^1H NMR. The crystal structure has been determined by X-ray single-crystal diffraction. The crystal belongs to monoclinic, space group P2 1/c with a = 8.982（2）, b = 17.908（4）, c = 13.219（3） A, β= 96.981（4）°, Z = 4, V= 2110.6（8） A^3, Dc = 1.347 g/cm^3, μ（MoKa） = 12.23 cm^-1, F（000） = 880, R = 0.0497 and wR = 0.1263. In the molecular structure of the title complex, the tin atoms are five-coordinated in a distorted trigonal bipyramidal geometry. A one-dimensional linear polymer is formed through an interaction between the O atoms of pyridine-3-carboxylic acid N-oxide and tin atoms of an adjacent molecule.

How Effective Is the Single-point Energy Calculation in Investigating the Reaction Mechanisms?New Decarboxylation Mechanism of Pyrrole-2-carboxylic Acid by Full Optimization with CPCM Solvation Model

The decarboxylation of pyrrole-2-carboxylic acid in acid solutions was elucidated by full optimization with the CPCM solvation model at the B3LYP/6-31 l＋＋G（d,p） level. Compared with the single-point energy calculation, CPCM full optimization is better to model solvent environments to gain reasonable reaction mechanisms. The π interactions play a significant role in the decarboxylation of pyrrole-2-carboxylic acid （R）. Firstly, the a hydrogen is protonated, but all of the carbonyl hydration pathways bear relatively higher energy barriers. The carbonyl group can rove over the pyrrole ring, but it does not lead to the speciation of pyrrole and protonated carbon dioxide for the latter is an energy-rich species. The decarboxylation mechanism proposed here is that, the protonated pyrrole-2-carboxylic acid （RH） decarboxylates via direct C-C bond cleavage with the aid of a water molecule to accommodate the proton on the carbonyl group.

A Facile Synthesis of 9,10-Dimethoxybenzo[6,7]- ox-epino[3,4-<i>b</i>]quinolin-13(6<i>H</i>)-one and Its Derivatives

A concise and efficient method for the synthesis of novel 9,10-imethoxybenzo[6,7]oxepino[3,4-b]quinolin13(6H)-one and its derivatives 7a-p has been developed via the intramolecular Friedel-Crafts acylation reactions of 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylic acids 6a-p with polyphosphoric acid (PPA) as catalyst and solvent under mild conditions. The key intermediates 6a-p were prepared through the in situ formation of ethyl 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylates 5a-p followed by hydrolysis with aqueous ethanolic sodium hydroxide solution. The novel synthetic method has the advantages of good yields, easy work-up, and environmentally friendly character, which may provide a novel highly efficient process for making quinoline and related azaheterocycle libraries.

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.

Two 1-(6'-O-acyl-β-D-glucopyranosyl)pyridinium-3-carboxylates from the flower buds of Lonicera japonica

Two new l-（6＇-O-acyl-β-D-glucopyranosyl）pyridinium-3-carboxylates,lonijaponinicotinosides A（1）and B（2）,were isolated from an aqueous extract of the flower buds of Lonicera japonica.Their structures were determined by spectroscopic data analysis,and confirmed by comparison with synthetic 1-β-Dglucopyranosylpyridinium-3-carboxylate.

Facile One-pot Synthesis of Ethyl 3-Alkyl-4-hydroxy-2-thioxothiazolidine-4-carboxylates

Ethyl 3-alkyl-4-hydroxy-2-thioxothiazolidine-4-carboxylates were prepared in excellent yields from the reaction of corresponding primary amines with carbon disulfide and ethyl 3-bromo-2-oxopropanoate in the presence of anhydrous potassium phosphate in DMF at room temperature within 1 h. The structures of the highly functionalized products were corroborated spectroscopically （IR, ^1H NMR, ^13C NMR, EI-MS） and by elemental analyses. A plausible mechanism for such type of cyclization was proposed.

An Efficient One-pot Synthesis of Aryl-substituted 1-(Thiazol-2-yl)-1H-pyrazole-3-carboxylates via a Hantzsch Synthesis-Knorr Reaction Sequence

The treatment ofα-bromoalkyl aryl ketones and 2-(propan-2-ylidene)hydrazine carbothioamide afforded 4-aryl-2-(2-(propan-2-ylidene)hydrazinyl)thiazoles via a Hantzsch-thiazole synthesis,which reacted with 4-aryl-2,4-diketoesters via a sequential Knorr-pyrazole reaction to deliver a variety of aryl-substituted ethyl 1-(thiazol-2-yl)-1Hpyrazole-3-carboxylates in a one-pot fashion with moderate to high yields.The key intermediates 4-aryl-2,4-diketoesters,existing as its enolic lithium salt,were synthesized in situ by a high-yield tert-BuOLi-mediated Claisen condensation of alkylphenones and diethyl oxalate.This class of elegant molecule comprises aryl groups on the two different heterocyclic cores,and the configurations of two representative molecules were determined by single crystal X-ray crystallography.