Preparation of α-Bromoketones and Thiazoles from Ketones with NBS and Thioamides in Ionic Liquids

Ketones smoothly reacted with NBS in the presence of a catalytic amount of ptoluenesulfonic acid to give α-bromoketones in good yields in typical ionic liquids, such as [bmim]PF6 and [bmpy]Tf2N, and the ionic liquids could be repeatedly used for the same reaction after the extraction of the α-bromoketones. Then, the one-pot conversion of ketones into thiazoles by the treatment with NBS, and subsequently with thioamides could be also carried out in [bmim]PF6 and [bmpy]Tf2N, respectively Thus, [bmim]PF6 and [bmpy]Tf2N could be used as recyclable reaction media for the preparation α-bromoketones and thiazoles from ketones.

Convenient synthesis of 2-arylbenzothiazoles and 2-arylnaphthothiazoles

Thiazoles including five 2-arylbenzothiazoles and two 2-arylnaphthothiazoles were synthesized using a simple synthetic strategy in this work.2-Arylbenzothiazoles and 2-arylnaphthothiazoles can be prepared by the reaction of methylaromatics with aniline or naphthylamine in the presence of elemental sulfur,respectively.All the seven thiazoles were characterized by the melting point measurement,FTIR,~1H NMR,^（13）C NMR and GC-MS analysis.

N-Methylpyridinium tosylate catalyzed green and efficient synthesis of some novel 2,4-disubstituted thiazoles and 4-thiazolidinones

A convenient solvent less cyclocondensation from thiosemicarbazone of benzofuranone and chloroacetic acid using an ionic liquid, N-methylpyridinium tosylate for obtaining novel 4-thiazolidinones in excellent yields is reported. Also, the green expedient synthesis of new 2,4-disubstituted thiazoles under grinding condition from phenacyl bromides and thiosemicarbazide derivatives in quantitative yields is reported.

Synthesis and Biological Evaluation of Quinazolonethiazoles as New Potential Conquerors towards Pseudomonas Aeruginosa

Novel quinazolonthiazoles were designed and synthesized as new potential antimicrobial agents by facile multi-step procedure from o-aminobenzoic acids and 2-acetylthiazole.A series of biological evaluation showed that compound 7d was the most effective quinazolonethiazole with superior activity to reference drugs chloramphenicol and norfloxacin.This active molecule displayed unob-vious bacterial resistance against P.aeruginosa,the low toxicity to normal hepatocytes,suitable pharmacokinetics and drug-likeness.The preliminary biological interaction suggested that quinazolonethiazole 7d might induce bacterial death by disturbing the membrane permeability,whilst preventing bacteria from growth by integrating into DNA and binding with topoisomerase IV.These findings provided significant background for the further development of quinazolonethiazoles as new potential drugs in combating drug-resistant pathogens.

TMSCI Promoted Direct sp3 C-H Alkenylation to Construct （E）-2-Styryl-tetrahydrobenzo[d]thiazoles

A high-efficient and stereo-specific approach for the preparation of biologically important （E）-2-styryl-tetra- hydrobenzo[d]thiazoles has been developed via TMSC1 promoted direct sp3 C-H alkenylation of 2-methyl-5,6-di- hydrobenzo[d]thiazol-7（4H）-one under metal-free conditions. Seventeen target compounds were synthesized in ex- cellent yields of 82%--98% under the optimal conditions of 300 mol% TMSCI at 110℃ for 2 h, and their chemical structures were elucidated by IR, NMR, ESI-MS, elemental analyses and X-ray crystallography analysis. A plausible mechanism was also proposed, and this method provided a good functional group conversion for the sp3 C-H substrates.

Synthesis, Photophysical Properties and TD-DFT Calculation of Fluorescent Dyes Based on Pyrenylthiazoles

Pyrene is one of significant fluorescent material and its fluorescence properties are excellent.It has been widely used for such as OLEDs,DSCs,LMOGs and so on[1-5].What＇s more,pyrene has been successfully applied to signaling the presence of metal ions,nucleic acids,proteins and so on[6-9].Thus,the development of the fluorescent dyes based on pyrene has been a research focus[10-12].However,the synthesis of many pyrene derivatives needed the high-cost coupling reaction such as Heck reaction and Suzuki reaction[1-3,10-12].

Control Effects of 9 Fungicides on Citrus Canker

In order to screen out effective fungicides for controlling citrus canker,the control effects of 9 fungicides on Jinhong bingtang orange canker were studied.The results showed that 77%cupric calcium sulfate WP,30%copper oxychloride SC,46%copper hydroxide WG,30%thiodiazole-copper SC and 40%zinc thiazole SC had better comprehensive control effect on citrus canker,6%benziothiazolinone WG had an average effect,3%zhongshengmycin AS,2%kasugamycin AS and 33.5%oxine-copper SC had poor control effect.Therefore,fungicides could be used alternately or choose compounded preparation.In addition,adjuvants could be considered in use,which was an effective way to enhance efficacy,reduced dosage and delayed pesticide resistance.

Synthesis of Some More New Sulfur-containing Heterocyclic Compounds as Biocidal Agents- Part II： Synthetic of 2-thioxo thiazole/thia diazole and 3-thioxo-1,3,4-triazole Derivatives

Some new 2-thioxo thiazole, 2-thioxo 1,3,4- thiadiazole and 3-thioxo-1,3,4-triazole derivatives （3-17） have been synthesized through ring closure reactions ofdithioic formic acid hydrazones 2 with functional reagents in different medium. Former structures of the products have been established by the help of elemental and spectral analysis. Most of the obtained targets showed a moderate activity towards some microbes in comparison with two antibiotics Pipercillin and Mycostatine.

Electronic Structure of some A3 Adenosine-Receptor Antagonist——A Structure Activity Relationship

DFT quantum chemical computations have been carried out at the B3LYP/6-31G (d) level. Full geometry optimization has been performed and equilibrium geometries for a new series of phenyl thiazoles have been located. Ground state electronic properties, charge density distributions, dipole moments and its components have been calculated and reported. Effect of substituents on the geometry and on the polarization of the studied series of compounds are analyzed and discussed. Some structural features have been pinpointed to underline the affinity and selectivity of the studied compounds as adenosine A3-receptor antagonists. Results of the present work indicate that activity towards A3 receptor sites is directly correlated with both of the polarity and the co-planarity of the thiazole.

Synthesis and plant-growth regulatory activities of novel imine derivatives containing 1H-1,2,4-triazole and thiazole rings

Eleven new imine derivatives 6 containing 1H-1,2,4-triazole and thiazole rings were synthesized by the condensation of 5-((1H- 1,2,4-triazol-1-yl)methyl)-4-tert-butylthiazol-2-amine with various substituted benzaldehydes.The structures of the title compounds were characterized by ~1H NMR,MS and elemental analysis.The plant-growth regulatory activities of these compounds were evaluated.The primary bioassay results indicated that these target compounds exhibited promising plant-growth regulatory activities.

Synthesis,Crystal Structure and Biological Activity of 2-(1-(3-Bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carbonyl)piperidin-4-yl)-N-isopropyl-1,3-thiazole-4-carboxamide

The title compound 2-（1-（3-bromo-1-（3-chloropyridin-2-yl）-1H-pyrazole-5-carbonyl）piperidin-4-yl）-N-isopropylthiazole-4-carboxamide（C21H22Br Cl N6O2 S,Mr = 536.04） has been synthesized,and its structure was characterized by IR spectra,1H-NMR,13C-NMR,EA,and single-crystal X-ray diffraction.The crystal of the title compound belongs to monoclinic system,space group P/c with a = 15.146（3）,b = 11.573（2）,c = 26.937（5） A,β = 103.64（3）°,V = 1839.0（6） A^3,Z = 4,Dc = 1.557 g/cm^3,μ（Mo Ka） = 0.71073 mm^-1,F（000） = 2192,R = 0.0601 and w R = 0.1392.There exist one intramolecular hydrogen bond at N–H···N and four intermolecular weak interactions at O（2）···H（1）,Cl（1）···H（12）,O（1）···Cl（1） and S（1）···O（2）.Bioassay results indicated that the title compound had good fungicidal and antiviral activities against tobacco mosaic virus.

Synthesis and Molecular Structure of 4-Chloromethyl-3-anilino-2-(4-methylbenzoylimido)thiazole

The title compound 2, 4-chloromethyl-3-anilino-2-（4-methyl-benzoylimido）thiazole, was prepared by the reaction of 1-p-methylbenzoyl-3-phenylaminothiourea 1 with 1,3-dichloro- acetone. The crystal is of monoclinic, space group P21/c, with a = 8.1712（15）, b = 10.998（2）, c = 19.134（4）A, β= 94.610（5）°, C18H16ClN3OS, Mr = 357.85, Z = 4, V = 1714.0（6）A^3, De= 1.387 g/cm^3, μ（MoKa） = 0.354 mm^-1, F（000） = 744, the final R = 0.0518 and wR = 0.1167 for 3189 observed reflections （I〉 2σ（I）. Its formation mechanism was proposed.

Synthesis and characterization of novel polyimides based on thiazole-containing diamine

A new kind of aromatic diamine monomer containing thiazole unit, 2-amino-5-（4-aminophenyl）-thiazole （AAPT）, was synthesized in three steps, starting from 4-nitroacetophenone. A novel thiazole-containing polyimide was prepared via the polycondensation of AAPT with 6FDA by one-step method. The resulting polyimide exhibits excellent solubility, film-forming capability and high thermal resistance.

Thiazolo[5,4-d]thiazole-based covalent organic framework microspheres for blue light photocatalytic selective oxidation of amines with O2

Covalent organic frameworks(COFs)with photoactive units have attracted significant interest in visible light photocatalysis and can present a metal‐free scenario for activating O_(2).As a typical photoactive unit,thiazolo[5,4‐d]thiazole(TzTz)has rarely been added to COFs.However,circumventing the low reversibility of TzTz,it could be embedded into the building blocks beforehand,along with other bonds likeβ‐ketoenamine in forming COFs.TzTz was embedded into 1,1′‐biphenyl‐4,4′‐diamine(BD)using this approach to produce 4,4′‐(TzTz‐2,5‐diyl)dianiline(DTz).Under organobase‐modulated solvothermal conditions,combining 1,3,5‐triformylphloroglucinol(Tp)with BD and DTz resulted in the production ofβ‐ketoenamine‐linked TpBD‐COF and TpDTz‐COF.Both TpDTz‐COF and TpBD‐COF are microspheres.TpDTz‐COF possessed more adequate separation and charge migration than TpBD‐COF.This resulted in superior performance for the blue light photocatalytic selective oxidation of benzylamine with O_(2).Furthermore,with O_(2) as the main oxidant,a wealth of benzylamines could be converted into imines over TpDTz‐COF.Mechanistic investigations substantiate that oxidation of benzylamines obeys an electron transfer pathway,in which superoxide anion(O_(2)•–)is the crucial reactive oxygen species.This study highlights the superiority of TzTz‐embedded COFs in developing effective photocatalytic systems for organic transformations.

Design, Synthesis and in vitro Evaluation of Thiazole Derivatives of Ibuprofen as Cyclooxygenase-2 Inhibitors

A series of thiazole derivatives of ibuprofen, as cyclooxygenase-2 Inhibitors, were designed, synthesized and in vitro evaluated.

Synthesis of bacillamide 3 and its analogue

The bacillamide 1 is a new algaecide from the marine bacterium Bacillus sp. SY-1. Its analogues bacillamide 3 and alkaloid 4 were firstly synthesized effectively from D-alanine. The key step was a coupling reaction via the mixed anhydride. All structures were confirmed by IH NMR and 13C NMR. The final compounds were confirmed by 1H NMR, 13C NMR and HRMS and the results are consistent with the reported natural products.

Synthesis of Novel Ferrocenyl-containing Thiazole Derivatives

Novel ferrocenyl-containing thiazole derivatives have been synthesized from 2-amino-4-ferrocenyl-5-（1H-1, 2, 4-triazole-l-yl）thiazole and acyl chloride. And their structures were determined by 1H NMR and elemental analysis.

Theoretical Study of Kinetics and Thermodynamics of Hetero Diels-Alder Reaction of Thiazole and Isothiazol with Thiophene-2,5-dione

DFT methods have been used to study the hetero Diels-Alder reaction of thiazole and isothiazole with thiophen-2,5-dione.The thermodynamic and kinetic parameters were calculated.The relative stabilities of the transition structures corresponding to the endo/exo stereoisomers have been rationalized on the basis of the secondary molecular orbital interactions.NBO analysis was carried out to calculate the synchronicity index.It was shown that all reactions are synchronous.A HOMO-LUMO energy gap shows both reactions are normal electron demand.

Synthesis, Crystal Structure and Fungicidal Activity of Ethyl 2-(3-(4-Fluorobenzamido)phenyl)-4-((4-fluorobenzoyl)oxy)thiazole-5-carboxylate

The target compound, ethyl 2-（3-（4-fluorobenzamido）phenyl）-4-（（4-fluorobenzoyl）oxy） thiazole-5-carboxylate, was synthesized by four-step procedures including N-protection, thionation, cyclization and acylation. Its structure was characterized by 1 H NMR, 13C NMR, HRMS and single-crystal X-ray diffraction. The target compound crystallizes as monoclinic crystal system, space group C2/c with a = 9.6097（19）, b = 14.246（3）, c = 33.070（7） ?, V = 4515.1（16） ?3, Z = 8, Dc = 1.496 Mg/m3, F（000） = 2096 and μ = 0.203 mm-1. There are 21864 reflections measured（4.94≤2θ≤55.96°）, of which 5357 were unique（Rint = 0.1418） and used in all calculations. The final R = 0.0581（I > 2σ（I）） and wR = 0.1453（reflections）. The target compound showed over 50% of growth inhibition against Physalospora piricola, Rhizoctonia cerealis and Sclerotinia sclerotiorum.