Novel One-Pot Multicomponent Synthesis of Substituted 2,3-Dihydro-2-(6-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl)phthalazine-1,4-diones and Substituted 3-[3-(N′-Benzylidene-hydrazino)-7H-[1,2,4] triazolo[3,4-b][1,3,4]thiadiazin-6-yl]-4-hydroxy-6-methyl-pyran-2-ones

A one-pot procedure has been developed for the synthesis of substituted 2,3-dihydro-2-(6-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-7H-[1,2,4]triazolo[3,4-b] [1,3,4]thiadiazin-3-yl)phthalazine-1,4-diones by reaction of 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one, 4-amino-5-hydrazino-4H-[1,2,4]triazole-3-thiol, and phthalic anhydrides in acetic acid medium. Similarly, a one-pot, three-component synthetic procedure has been developed for substituted 3-[3-(N¹-benzylidene-hydrazino)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-6-yl]-4-hydroxy-6-methyl-pyran-2-ones from 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one, 4-amino-5-hydrazino-4H-[1,2,4]triazole-3-thiol, and various aromatic aldehydes in absolute ethanol and a few drops of glacial acetic acid.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Phase Transfer Catalyzed Synthesis of 1, 2-Bis[（3-aryl）-s-triazolo- [3, 4-b]-[1, 3, 4]thiadiazole-6-yl]ethanes

s-Triazolo[3, 4-b]-[1, 3, 4]thiadiazole derivatives have been paid attractive attention due to their significantly biological activities1-5, including antibacterial, antifungal, anticancer, relaxing vascular activities. They are highly important heterocyc…     

Synthesis of 3-Substituted-6-(2,4-Dichlorophenyl)-s-Triazolo[3.4-b]-1,3,4-Oxadiazoles

2,5-DisubstitUted-l,3,4-oxadiazolederivativeshavebeenrePort6dtoshowantidrigal1,antiin-flamrnatoof,andplantgrowthpromoter3activities-3,4-Disubstituted-l,2,4-triazolecompoundsalsopossessantifimgal',andplantgrowthpromote/achvities.Authors6havereportedthat(3-bmpl4-aroyl-l,2,4-triazole-5-yl)[5-(3,4,5-triInethoxylphenyl>l,3,4roxadiazole-2-yl]sulfidesshowedsomeantifungalactivity.lnordertoscreennewcompoundsofpossessingphysiologicalactivity'andstUdythereactionruleofnucleophilicdisplacementwehavedevelo…     

Synthesis and Crystal Structure of 1,2-Bis(1-phenyl-3-methylthio- 4-iminopyrazolo[3,4-d]pyrimidin-5-yl) ethane

1 INTRODUCTION As purine analogs, pyrzolo[3,4-d]pyrimidines have anti-tumor[1], antibacterial[2] and anti-leukemic activities[3,4]. Few of these, however, have been studied for pesticidal activity. It is reported that some substituted pyrzolo[3,4-d]pyrimidines have good fungicidal activity[5~7]. These prompted us to study pyrazolo[3,4-d]pyrimidines analogs further. It is shown that two possible products can be formed in the reaction of ethyl N-pyrazolylformimidate with alkylamines as sh…     

Synthesis of 1, 4-Bis[3-N-propionyl-2-aryl-1, 3, 4- oxadiazoline-5-yl]phenylenes

1, 3, 4-Oxadiazoline derivatives are found to possess significant biological activities such as antifungal1, insecticidal2, CNS depressant3-5, anticonvulsant effects and plant growth accelerator. They are highly important heterocycles, and have been used …     

Synthesis and Antibacterial Activity of 8-Substituted Phenyl-1-pyridin-3-yl-5H-bis[1,2,4]triazolo[3,4-b;4′,3′-d][1,3,4] thiadiazines

1,2,4-Triazole derivatives, such as 1, 2, 4-triazolo[3, 4-b]thiadiazoles and 1, 2, 4- triazolo [3,4-b]thiadiazolines, as potent antibacterial agents have been widely investigated1-4. Chemically, their structures mainly focus on bi-fused heterocycles, but tri-fused derivatives have not been reported. In continuing our previous works5-8 on finding better antibacterial agents, we herein reported the synthesis and pharmacological evaluation for completely new class of compounds 4a~e with antibacte…     

Synthesis and Crystal Structure of 3,6-Bis（4-methyl-1,2,3-thiadiazol-5-yl）-1,2,4-triazolo[3,4-b][1,3,4]thiadiazole

The compound 3,6-bis(4-methyl-1,2,3-thiadiazol-5-yl)-1,2,4-triazolo[3,4-b][1,3,4] thiadiazole(C9H6N8S3,Mr = 322.40) has been synthesized by the reaction of 4-amino-3-(4-methyl-1,2,3-thiadiazolyl)-5-mercapto-1,2,4-triazole with 4-methyl-1,2,3-thiadiazol-5-carboxylic acid and phosphorus oxychloride,and its structure was characterized by IR,1H NMR,EI-MS,elemental analysis and single-crystal X-ray diffraction.The crystal of the title compound belongs to monoclinic,space group C2/c with a = 2.0053(4),b = 1.3081(3),c = 1.0556(2) nm,β = 112.69(3)°,Z = 4,V = 2.5548(9) nm3,Dc = 1.676 g/cm3,μ = 0.582 mm-1,F(000) = 1312,R = 0.0546 and wR = 0.1523.X-ray analysis indicates that all rings are essentially planar in this molecule,and an intermolecular hydrogen bond C(9)-H(9)…N(2) and weak intramolecular interactions between S(1)…N(7),S(3)…N(1) and S(2)…N(4) are observed.     

Synthesis and electrochemical properties of 2,6-bis（6-aryl-[1,2,4]- triazolo[3,4-b][1,3,4]-thiadiazole-3-yl）pyridines

By the condensation of 2,6-bis（4-amino-5-mercapto-[1,2,4]-triazoles-2）pyridine with aromatic acid in the presence of phosphorus oxychloride. Compounds of 2,6-bis（6-aryl-[1,2,4]-triazolo[3,4-b][1,3,4]-thiadiazole-3-yl）pyridines were synthesized. Their structures were confirmed by IR, ^1H NMR spectroscopies and elemental analysis. Their electrochemical behavior and cyclic voltammogram also were be studied. The results showed that they have high ionization potentials and good affinity.     

Synthesis and Structure of 2-(1Н-Indol-1-yl)-6-ferrocenyl-4-(2-chloroimidazo[1,2-a]pyridin-3-yl)pyrimidine

A 2,4,6-trisubstituted pyrimidine including a 2-(1H-indol-1-yl) substituent was synthesized by the reaction of 1-ferrocenyl-3-(2-chloroimidazo[1,2-a]pyridin-3-yl)propanone with 2,5-dimethoxytetrahydrofuran. The structure of the synthesized compound was confirmed by IR and ¹Н NMR spectroscopy, and X-ray diffraction analysis. It has been shown that the ferrocene-containing compounds synthesized in the present work all demonstrate intramolecular charge transfer which is evidenced by the observation of the corresponding absorption bands with λ ^abs_max > 480 nm. The oxidation potential of ferrocene (E ^Fc_ox ) in all the compounds is higher than 700 mV.

     

Comparative Studies of 1,4-Bis[2-（4-Pyridyl）ethenyl]-benzene Using Density Functional Theory

The optimized molecular structure and harmonic vibrational frequencies of a 1,4-bis[2-(4-pyridyl)ethenyl]-benzene(BPENB)molecule were calculated via five popular density functional theory(DFT)methods.On the basis of the comparison between calculated and experimental results,it is concluded that the B3PW91 and B3LYP methods are superior to the others in optimizing structures,and the BPW91 method reproduces the observed fundamental frequencies most satisfactorily.     

Synthesis and Crystal Structure of N-（1,3,4-Thiadiazol-2-yl）-1-[ 1-（6-chloropyridin-3- yl）methy]-5-methyl-lH-[1,2,3]triazol-4-carboxamide

The crystal structure of the title compound （C12H10ClN7OS, Mr= 335.78） has been determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group Pi with a = 8.4093（11）, b = 9.4430（12）, c = 11.1454（14） A, α = 95.508（2）, β = 111.366（2）, γ = 115.259（2）°, V = 711.42（16） A3, Z = 2, Dc = 1.568 g/cm3, F（000） = 344, μ（MoKα） = 0.428 mm-1, the final R = 0.0476 and wR = 0.1243 for 2353 observed reflections （I 〉 2o（/））. The dihedral angles between the pyridine and triazole, thiazole and triazole, and pyridine and thiazole rings are 69.2（1）, 9.2（1） and 72.7（1）°, respectively. Intramolecular C（8）--H（8B）...O（1） and N（5）-H（5A）..-N（4） as well as intermolecular C（5）-H（5）...S（1）, C（3）-H（3）.,.N（6） and N（5）-H（5A）...N（1） hydrogen bonds together with weak C-H...Ir hydrogen-bonding and π-π stacking interactions contribute to the stability of the structure. There is also evidence for significant electron delocalization in the triazolyl system.     

3, 6-二取代-均三唑并[3, 4-b]-1, 3, 4-噻二唑的合成

研究了2-苯基-1, 2, 3-三唑-4-羧酸(1)与3-烷基/芳基-4-氨基-5-巯基-1, 2, 4-三唑(2a～o)在POCl~3催化下, 脱水缩合得到15个新的3-烷基/芳基-6-(2'-苯基-1', 2', 3'-三唑-4'-基)均三唑并[3,4-b]-1, 3, 4-噻二唑类化合物(3a～o)。     

Synthesis and Crystal Structure of E,E-1,4-Bis[4''''-(N,N-di-n-butylamino)- styryl]-2,5-dimenthoxybenzene

1 INTRODUCTION In recent years, a great deal of interest has been focused on two-photon initiated photopolymeri- zation (TPIP) exploring some periodical microstruc- tures by means of TPIP[1～3]. The technique will have wide applications in many fields, such as 3D optical mmory[4] and a fabrication of coupling gra- ting in the polymeric waveguide[5], and especially the fabrication of three-dimensional photonic crys- tal[6]. In this work, effective initiator is a key for TPIP. At pre…     

Preparation and Crystal Structure of 3-（2-Hydroxyphenyl） -6- （4-nitrophenyl）-7H- 1,2,4-triazolo[3,4-b][1, 3,4]thiadiazine

Introduction3,6- Disubstituted- 7H- 1 ,2 ,4- triazolo[3,4- b][1 ,3,4]thiadiazines are amongst the various hete-rocycles that received considerable attention duringthe last two decades as potential biologically activeagents.This kind of N- bridged heterocycles hasbeen reported to possess the wide spectrum of bio-logical properties,such as antimicrobial[1] ,an-tibacterial,antifungal[2 ] ,antiinflammatory[3 ] ,di-uretic[4] ,anthelmintic,and analgesic properties[5] .They can be also used as plant…     

Synthesis of new conjugated copolymers containing 4,8-bis(dodecyloxy)benzo[1,2-b:4,5-b′]dithiophene/5,7-bis(3,4-diethylthien-2-yl)-2,3-diphenylthieno[3,4-b]pyrazine and 4,8-bis(dodecyloxy)benzo[1,2-b:4,5-b′]dithiophene/4,6-di(3,4-diethylthien-2-yl)-thieno[3,4-c][1,2,5]thiadiazole derivatives for photovoltaic applications

Two new donor-acceptor narrow-band-gap photovoltaic copolymers containing various electron-acceptor functional groups, such as thienopyrazine and thienodithiazole derivatives, are synthesized under the conditions of the Suzuki polycondensation reaction and characterized via ¹H NMR spectroscopy and GPC. The optical, electrochemical, and photovoltaic properties of the polymers are examined in detail. Both copolymers have good solubilities, high thermal stabilities, broad absorption regions (350–950 nm), relatively low levels of the highest occupied molecular orbital (?5.01 and ?5.02 eV for polymers I and II, respectively), and narrow band gaps (1.31 and 1.41 eV, respectively). Photovoltaic devices based on a polymer-II-PC₆₀BM (1: 3, wt/wt) mixture under AM 1.5 irradiation of 100 mV/cm² exhibit a power-conversion efficiency of ～0.29%, a short-circuit current of 1.45 mA/cm², an open-circuit voltage of V _oc = 0.67 V, and a fill factor of 0.30. These results are evidence that thienopyrazine functional groups are attractive as electron-acceptor building blocks in organic electronics.     

Synthesis,Reactions, and Antiviral Activity of 1-(1H-Pyrazolo[3,4-b]pyridin-5-yl)ethanone and Pyrido[2′,3′:3,4]pyrazolo[5,1-c][1,2,4]triazine Derivatives

1-(3-Amino-6-methyl-4-pyridin-3-yl-1H-pyrazolo[3,4-b]pyridin-5-yl)ethanone (3) was obtained in very pure state and used as a good starting material for the present study. It diazotized to give the corresponding diazonium salt 9 and also reacted with phenyl isothiocyanate to give the corresponding thiourea derivative 4. Compound 4 was used for the preparation of thiazole derivatives 5–8 via the reaction with active halogen-containing compounds. On the other hand, compound 9 coupled with several active –CH₂- containing compounds to afford the corresponding triazine derivatives 10–17. Considering the data from IR, ¹ H NMR, mass spectra, and elemental analyses, the chemical structures of the newly synthesized heterocyclic compounds were elucidated. Cytotoxicity, anti-HSV1, and anti-HAV-MBB activity were evaluated for the newly synthesized heterocyclic compounds.