Synthesis of pyrazine-2,3-dicarbonitrile and 1,2,4-triazine-5(4H)-one derivatives from furan-2,3-diones

The reaction of furan-2,3-diones with S-methylisothiosemicarbazide hydroiodide yielded novel 1,2,4- triazine-5（4H）-ones, and reaction of furan-2,3-diones with diaminomaleonitrile led to the formation of pyrazine-2,3-dicarbonitrile derivatives, and the hydrolysis of these products led to the formation of more new pyrazine-2,3-dicarbonitrile derivatives. These compounds are potential herbicides and pesticides.

Synthesis, Crystal Structure and Antitumor Activity of 2-(3-Methyl-5-(methylthio)-4H-1,2,4-triazol-4-yl)isoindoline-1,3-dione

The title compound 2-（3-methyl-5-（methylthio）-4H-1,2,4-triazol-4-yl）isoindoline- 1,3-dione （C12H10NaO2S, Mr= 274.30） has been synthesized by a three-step procedure including the cyclization, hydrazinolysis and substitution reactions, and its crystal structure was determined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P2/c with a = 12.264（3）, b = 14.646（3）, c = 14.349（4） A,β = 91.69（3）°,μ = 0.255 mm1, Mr = 274.30, V = 2576.2（10） A3, Z =8, Dc = 1.414 g/cm3, F（000） = 1136, R = 0.0487 and wR = 0.1329 for 4048 observed reflections with I 〉 2σ（I）. In addition, the preliminary bioassay suggested that the title compound 6 exhibits relatively good antitumor activity against HT-29 and MCF-7.

Synthesis and Infrared Spectra Computation of Sterically Congested 2,2-Disubstituted Indane-1,3-dione Derivatives

Sterically congested 2,2-disubstituted indane-1,3-dione derivatives have been syn-thesized and characterized by 1H NMR,13C NMR,FT-IR and elemental analysis.The B3LYP/HF calculations for computation of IR spectra have been carried out for the title compounds at the 6-31G and 6-311＋＋G basis set levels.Predicted vibrational frequencies have been assigned and compared with the experimental FT-IR spectra and they are supported each other.

A facile one-pot synthesis of new thieno-[2,3-d]pyrimidine-2,4(1H,3H)-dione derivatives

A facile one-pot synthesis of new 3-arylthieno[2,3-d]pyrimidine-2,4（1H,3H）-diones via base-catalyzed cyclocondensation of ethyl 2-amino-4,5-dimethylthiophene-3-carboxylate with aryl isocyanates is described.

Synthesis, Dimer Crystal Structure and Herbicidal Activity of 2-(4-Ethoxybenzoyl)cyclopentane-1,3-dione

The title compound 2-（4-ethoxybenzoyl）cyclopentane-1,3-dione（C14H14O4） was synthesized, and its crystal structure was studied. It crystallized in the triclinic system, space group P1 with a = 8.980（2）, b = 9.080（2）, c = 15.482（3） A, α = 93.49（3）, β = 93.84（3）, γ = 107.27（3）°, Dc = 1.365 g/cm^3, Z = 4, λ = 0.71073A, μ（MoKα） = 2.769 mm^-1, Mr = 246.25, V = 1198.5（4）A3, F（000） = 520, the final R = 0.0559 and wR = 0.1278 for 2301 observed reflections with I 〉 2σ（I）. In the crystalline state, the molecular skeleton contains one enol grouping, which is intramolecularly hydrogen bonded to a neighboring keto O atom. Preliminary bioassay result showed that this compound provided 93.8% and 87.2% control of B. campestris and A. retroflexus at post-emergence at 375 g/hm^2.

The Intramolecular Coupling Reaction of 1,6-Bis(1-Alky1-2-Methylindol-3-yl)hexane-1,6-dione Induced by Low-valent Titanium

The intramolecular reductive coupling reaction of 1,6-bis(subshtuted indolyl)hexane-1,6-dione using zero-valent titanium reagent as catalyst proderes the novel photochromic 1,2-diheterocyclic cyclohexenes 2, together with unexpected compounds 3

Facile synthesis of[1,2,4]triazino[4,3-b][1,2,4,5]tetrazepin derivatives by a one-pot reactions using 4-amino-3-hydrazinyl-6-methyl-1,2,4-triazin-5(4H)-one

4-Amino-3-mercapto-6-methyl-l,2,4-triazin-5（4H）-one 1 converted to 4-amino-6-methy-3-（methylthio）-1,2,4-triazin-5（4H）-one by methylation with methyl iodide.Controlled hydrazination of the resulting compound afforded 4-amino-3-hydrazinyl-6- methyl-l,2,4-triazin-5（4H）-one 2 as a building block,to the synthesis of some novel derivatives of[1,2,4]triazino- [4,3,b][1,2,4,5]tetrazepine 3-6,by the reaction with 3-chloropentane-2,4-dione,chloro acetonitrile,1,3-dichloroacetone,and methyl bromoacetate.This general synthetic procedure can be extended to the preparation of wide variety of tetrazepines using 1,2- bielectrophiles derivatives.

Isatin decreases Bax protein expression in the substantia nigra of a mouse model of Parkinson's disease

The present study observed the action of 1H-indole-2, 3-dione （isatin） on Bax protein expression in the substantia nigra of a Parkinson＇s disease animal model. Parkinson＇s disease-like behaviors were induced in C57BL/6J mice treated with 1-methyl-4-phenyl-1,2, 3, 6-tetrahydropyridine （MPTP） Bax protein expression was significantly reduced in isatin （100, 200 mg/kg）-pretreated mice. Results demonstrate that isatin plays a neuroprotective role in mice treated with MPTP by down-regulating Bax protein expression.

Design, Synthesis and Herbicidal Activities of Tetrahydroisoindoline-1,3-dione Derivatives Containing Alkoxycarbonyl Substituted 2-Benzoxazolinone

Several different alkoxycarbonyl-substituted 2-benzoxazolinone moieties have been incorporated into a tetrahy- droisoindoline-1,3-dione scaffold to provide 25 compounds （1a-lu and 2a-2d）. The structures of these compounds were confirmed by 1H and 13C NMR, HRMS and X-ray single-crystal diffraction. Some of these compounds （1g, 1h, 1j, 1k） exhibited excellent herbicidal activities against Abutilon theophrasti, Amaranthus retroflexus and Eehinochloa crus-galli at a rate of 375 g AI·ha^-1. Among them, compounds lh and 1j displayed the best post-emergence herbicidal effect against Abutilon theophrasti with ED50 values of 1.8 and 5.3 g AI·ha^-1, respectively, which are superior to that of the commercial acifluorfen （44.3 g AI·ha^-1）. Field trials demonstrated that compound lh exhibited similar herbicidal activity to a high concentration atrazine, and found to be safer for maize than atrazine. The results of this study therefore show that compound lh could potentially be used as a post-emergence herbicide for maize fields.

Functional Ionic Liquids Promoted Double Michael Reaction of Benzofuran-3-one or 1-1ndone and Symmetric Dienones： Construction of Spiro[benzofuran-2,1′-cyclohexane]-3-one or Spiro[cyclohexane-1,2′-indene]-1′,4（3′H）-dione Derivatives

The double Michael reactions between benzofuran-3-one or 1-indone and symmetric dienones in the presence of catalytic ionic liquids were successfully developed and spiro[benzofuran-2, 1′-cyclohexane]-3-one or spiro[cyclo- hexane-1,2′-indene]-1′,4（3′H）-dione derivatives containing a spiro quaternary stereogenic center, which widely exist in biologically active products and building blocks in organic synthesis, were obtained in excellent yields （up to 99%）. This catalytic system was also extended to the double Michael reaction of less reactive 1-indone and the desired products were also obtained in 31%-62% yields. The catalytic system was highly active and efficient for a broad of substrates under mild conditions.

(S)-3-aminopiperidine-2,6-dione is a biosynthetic intermediate of microbial blue pigment indigoidine

The biosynthetic investigations of microbial natural products continuously provide powerful biocatalysts for the preparation of valuable chemicals.Practical methods for preparing(S)-3-aminopiperidine-2,6-dione(2),the pharmacophore of thalidomide(1)and its analog drugs,are highly desired.To develop a biocatalyst for producing(S)-2,we dissected the domain functions of IdgS,which is responsible for the biosynthesis of indigoidine(3),a microbial blue pigment that consists of two 2-like moieties.Our data supported that the L-glutamine tethered to the indigoidine assembly line is first offloaded and cyclized by the thioesterase domain to form(S)-2,which is then dehydrogenated by the oxidation(Ox)domain and finally dimerized to yield 3.Based on this,we developed an IdgS-derived enzyme biocatalyst,IdgS-Ox^(*)R539A,for preparing enantiomerically pure(S)-2.As a proof of concept,one-pot chemoenzymatic synthesis of 1 was achieved by combining the biocatalytic and chemical approaches.

Dynamic changes in cerebral microcirculation and hypoxia in the early stages of diffuse axonal injury

This study demonstrated that damage to the cerebral microvasculature, the formation of microthrombi and swelling of vascular endothelial cells occur early and peak 12 hours after injury in a rat model of diffuse axonal injury. Moreover, these pathological changes were most evident in the cerebral cortex. Cerebral microcirculatory dysfunction peaked later and had a shorter duration than axonal injury. In addition, the radioactive imaging agent, 99Tcm-4, 9-diaza-2, 3, 10, 10- tetramethyldodecan-2, 11 -dione dioxime, was used to visualize the dynamic changes that occur in tissue with cerebral hypoxia. The results demonstrated that cerebral hypoxia occurs at an early stage in diffuse axonal injury. Cerebral hypoxia was evident 12 hours after injury and declined slightly 24 hours after injury, but was significantly higher than in the control group. The pathological changes that underpin microcirculatory dysfunction did not occur at the same time as axonal injury, but did occur simultaneously with neuronal injury. Cerebral hypoxia plays a key role in promoting the secondary brain injury that occurs after diffuse axonal injury.

Regioselective Synthesis of Fused Azo-linked Pyrazolo[4,3-e]pyridines Using Nano-Fe3O4

A multicomponent reaction for the synthesis of fused azo-linked pyrazolo[4,3-e]pyridines from 3-amino-5-methylpyrazole, indan-l,3-dione and synthesized azo-linked aldehydes using nano-Fe304 as an effective and reusable catalyst is reported. The present methodology offers several advantages, such as a simple procedure with an easy work-up, short reaction times, high yields, and the absence of any volatile and hazardous organic sol- vents.

Improved microwave-assisted catalyst-free synthesis of9-aryl-5,9-dihydropyrimido[4,5-d][1,2,4]triazolo[1,5-a]pyrimidine-6,8(4H,7H)-dione derivatives

Agreen regioselective synthesis of some new and known 9-aryl-5,9-dihydropyrimido[4,5-d][l,2,4]triazolo[1,5-a]pyrimidine-6,8（4H,7H）-diones has been described via the microwave-assisted one-pot reaction of 3-amino-1H-1,2,4-triazoles,aromatic aldehydes and barbituric acids under solvent- and catalyst-free conditions.This operationally simple procedure is less laborious and provides a better scope than previously reported procedures.