Synthesis and Crystal Structure of 4-Salicyli deneamino-3-methyl-1,2,4-triazol-5-thione

The crystal structure of 4-salicylideneamino-3-methyl-1,2,4-triazol-5-thione 1 (C10H10N4OS, Mr = 234.28) has been determined by single-crystal X-ray diffraction method. The crystal belongs to monoclinic, space group P21/n with a = 12.697(3), b = 7.4072(15), c = 12.750(3) , b = 117.68(3), V = 1061.85(4) 3, Z = 4, Dc = 1.465 g/cm3, m = 0.288 mm-1 and F(000) = 488. R = 0.0584 and wR = 0.1642 for 2660 unique reflections with 2130 observed ones (I > 2s(I)). The results confirmed that the configuration of the title compound at the azomethine C=N bond is E and 1 can be assigned as the thione tautomeric form. All atoms of the title compound are essentially coplanar.

Studies on Acylthiosemicarbazides and Related Heterocycles(ⅪⅤ)——Synthesis and Bactericidal Activity of 1-(5-(3-Pyridyl)-2H-Tetrazol-2-ylacetyl) -4-Arylthiosemicarbazides and 3- (5- (3-Pyridyl)-2H-Tetrazol-2-ylmethyl)-4-Aryl-1,2 ,4-Triazole-5-Thiones

Introduction In the preceding paper it was described that various 1-acyl-4-substituted thiosemicarbazides and their derivatives exhibited a broad spectrum of antibacterial activities. Kothari pointed out that some heterocycles linked with tetrazole and 1,2,4-triazole can be used as antiinflammatory agent. We have also demonstrated that both 3-(5-a- naphthyl)-2H-tetrazol-2-ylmethyl)-4-aryl-1,2,4-triazole-5-thiones and 3-(3-pyridyl)-

Syntheses and Crystal Structures of 4-Amino-3-(3-hydroxypropyl)-1H-1,2,4-triazole-5(4H)-thione and 6-(4-Biphenylyl)-3-(3-hydroxypropyl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazine

Starting with y-butyrolactone, 4-amino-3-（3-hydroxypropyl）-1H-1,2,4-triazole-5-（4H） thione 1 was prepared, and cyclization of it with 4-phenylbromoacetophenone gave 6-（4-biphenylyl）- 3-（3-hydroxypropyl）-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazine Ⅱ. The structures of Ⅰ and Ⅱ were determined by elemental analyses, IR, ^1H NMR, ^13C NMR, and X-ray diffraction. Crystal data for 1： C5H10N4OS, Mr = 174.23, monoclinic system, space group P21/c, a =8.4568（6）, b = 22.8905（16）, c = 9.2625（6） A, β= 114.172（1）°, V= 1635.82（19） A^3, F（000） = 736, Z= 8, Dc = 1.415 g/cm^3, 2 λ=0.71073 A,μ = 0.346 mm^-1 and the final R = 0.0603 for 2870 unique reflections with 1993 observed ones （I 〉 2σ（I）. Crystal data for Ⅱ： C19H18N4OS, Mr = 350.43, monoclinic system, space group P21/c, a = 6.7481（7）, b = 8.2647（8）, c = 30.075（3） A, β= 94.445（2）°, V= 1672.3（3） A3, F（000） = 736, Z = 4, Dc = 1.392 g/cm^3, λ=0.71073 A,μ= 0.209 mm^-1 and the final R = 0.0667 for 3000 unique reflections with 2534 observed ones （I 〉 2σ（I））. In the crystal of compound Ⅱ, the five-membered triazole ring and two benzene rings are coplanar, while the six-membered thiadiazine ring is slightly distorted, with an r.m.s deviation of 0.227（1） A. Some hydrogen bonding interactions are observed and π-π stacking interactions between adjacent molecules are found in the packing diagrams of the two compounds.

Synthesis, Crystal Structure, Antibacterial Activities and Theoretical Computation of 3-(2-Hydroxybenzly)-4-(4-isopropylbenzyl- ideneamino)-(1H)-1,2,4-triazole-5-thione

The title compound C18H18N4OS has been synthesized by the reaction of 3-（2-hydroxy- benzyl）-4-amino-（1H）-1,2,4-triazole-5-thione with 4-isopropylbenzaldehyde in ethanol and characterized by IR, ^1H NMR spectra and elemental analysis. Its structure was determined by X-ray diffraction analysis. The crystal belongs to monoclinic, space group P21/c with a = 11.605（2）, b = 7.401（1）, c = 20.339（2） A, β= 103.05（2）°, V= 1701.8（4） A^3, Z = 4, Mr = 338.42,μ = 0.202 mm^-1, Dc = 1.321 g/cm^3 and F（000） = 712. The structure was solved by direct methods and refined to R = 0.0428 and wR = 0.1069. Due to the intramolecular O-H…N hydrogen bond and π-π stacking interactions between the benzene （C（1）～C（6）） and triazole rings, the two planes are essentially coplanar. Their biological activities have been measured, showing this type of compound has certain antibacterial activity for Staphylococous aureus and Bacillus subtilis. Based on the quantum chemistry calculation at the RHF/6-31G level, the frontier orbitals and electrostatic potential of the title compound were also discussed.

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, Crystal Structure and Antitumor Activity of 4-tert-Butyl-N-(2-fluorophenyl)-5- (1H-1,2,4-triazol-1-yl)-thiazol-2-amine

The title compound has been synthesized by the reaction of 1-bromo-3,3-dime- thyl- 1 - （1 H- 1,2,4-triazol- 1 -yl）butan-2-one with 1 -（2-fluorophenyl）thiourea, and its crystal struc- ture was determined by single-crystal X-ray diffraction. The crystal belongs to the orthorhombic system, space group Pbca with a = 15.2568（6）, b = 12.1533（5）, c = 16.7307（7） A, Z = 8, V = 3102.2（2） A3, Mr = 317.39, Dc = 1.359 g/cm3, S = 1.05, μ = 0.223 mm-1, F（000） = 1328, the final R = 0.034 and wR = 0.097 for 2590 observed reflections （I 〉 2σ（I））. X-ray crystal structure presents the intramolecular N-H…N hydrogen bond, which plays an important role in stabilizing the crystal structure. In addition, the preliminary biological test on the title compound shows good antitumor activity, with IC50 of 0.122 μmol/mL against the Hela cell line.

Synthesis, Crystal Structure and Antitumor Activity of 4-(tert-butyl)-5-(1H-1,2,4-triazol-1-yl)-N-(2-hydroxy-3,5-diiodinebenzyl)-thiazol-2-amine

The title compound, 4-（tert-butyl）-5-（1 H- 1,2,4-triazol- 1 -yl）-N-（2-hydroxy-3,5-diio- dinebenzyl）thiazol-2-amine, was synthesized via the reduction of 4-（tert-butyl）-5-（1H-l,2,4- triazol-l-yl）-N-benzylidene-thiazol-2-amine with NaBH4, and its crystal structure was determined by single-crystal X-ray diffraction. The compound crystallizes in monoclinic system, space group P21/c with a = 7.91944（19）, b = 10.5250（3）, c = 24.4985（6） A, Z = 4, V = 2041.66（9） A3, Mr = 599.22, Dc = 1,949 Mg/m3, S = 1.120, p = 3.203 mm-1, F（000） = 1152, the final R = 0.0283 and wR = 0.0592 for 3490 observed reflections （I 〉 2σ（I））. X-ray analysis displays that the crystal water takes part in three intermolecular hydrogen bonds of O（2）-H（2A）…O（1）, O（2）-H（2B）…N（I） and N（5）-H（5）…O（2）, and an octatomic ring R^（8） is formed via intramolecular hydrogen bond of O（I）-H（IA）…N（4）. Furthermore, the I…I contacts are involved in stabilizing the overall three-dimensional network structure. The preliminary biological test shows the title compound has good antitumor activity with the IC50 value of 26 μM against the Hela cell line.

Synthesis,Crystal Structure and Antitumor Activity of(E)-N-(4-Fluorobenzylidene)-3-(methylthio)-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazol-4-amine

The crystal structure of the title compound（E）-N-（4-fluorobenzylidene）-3-（methylthio）-5-（3,4,5-trimethoxyphenyl）-4 H-1,2,4-triazol-4-amine（C_（19）H_（19）FN_4O_3S,Mr = 402.44） was synthesized,and its structure was characterized by 1 H-NMR,13 C-NMR,ESI-MS and single-crystal X-ray diffraction.The crystal belongs to the triclinic system,space group P1 with a = 9.228（13）,b = 10.364（14）,c = 10.641（14） ？,α = 85.323（3）,β = 75.172（2）,γ = 80.903（3）°,μ = 0.20 mm^（-1）,M_r = 402.44,V = 970.64（10） ？~3,Z = 2,D_c = 1.377 g/cm^3,F（000） = 420,R = 0.0484 and wR = 0.1474 for 3181 observed reflections with I 〉 2σ（I）.In addition,the preliminary bioassay indicated that the title compound 5 exhibits better inhibitory activity against Hela than 5-fluorouracil.

Synthesis, Crystal Structure and Antitumor Activity of (E)-1-(7-Methoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5- yl)-3-(2-methoxyphenyl)-2-(1H-1,2,4-triazol-1-yl)propenol

The title compound, （E）-1-（7-methoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5-yl）- 3-（2-methoxyphenyl）-2-（1H-1,2,4-triazol-1-yl）propenol （3a）, was synthesized by the Aldol con- densation reaction of 1-（7-methoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5-yl）-2-（1,2,4-triazol- 1-yl）ethanone with 2-methoxybenzaldehyde and then reduced with NaBH4, and its crystal structure was determined by single-crystal X-ray diffraction： monoclinic system, space group P21 with a = 6.2002（3）, b = 12.8452（7）, c = 13.2257（7） ？, Z = 2, V = 1031.23（9） ？3, Mr = 407.46, Dc = 1.312 Mg/m3, S = 1.054, μ = 0.091 mm-1, F（000） = 432, the final R = 0.0353 and wR = 0.0769 for 3161 observed reflections （I 〉 2σ（I））. X-ray analysis displays that the title compound adopts an E configuration for the C（7）=C（8） double bond and S configuration for the chirality center with the specific rotation of –63.75°. Furthermore, the stability of the crystal was maintained through the intermolecular hydrogen bond O（1）–H？？？N（3）. The antitumor assay exhibits that the title compound 3a （E configuration） has a good antitumor activity against the Hela cell line with the IC50 value of 36.9 μM, which is better than that of 3b （Z configuration）.

Non-isothermal Kinetics of the Thermal Decomposition of 3-Nitro-1,2,4-triazol-5-one Magnesium Complex

The thermal decomposition of 3-nitro-1,2,4-triazol-5-one magnesium complex and its kinetics were studied under the non-isothermal condition by DSC and TG/DTG methods. The kinetic parameters were obtained from analysis of the DSC and TG/DTG curves by the Kissinger method,the Ozawa method,the differential method and the integral method. The most probable mechanism functions for the thermal decomposition of the first stage,the second stage and the third stage were suggested by comparing the kinetic parameters. The entropy of activation (ΔS ≠),enthalpy of activation (ΔH ≠) and free energy of activation (ΔG ≠) at Tpdo are -66.74 J·mol -1 ·K -1 ,119.2 kJ·mol -1 and 152.44 kJ·mol -1 ,respectively.

Synthesis, Crystal Structure and Antifungal Activity of a New Zn(Ⅱ) Complex Based on 4-(5-(Pyridin-3-yl)-4H-1,2,4-triazol-3-yl) Benzoic Acid

A new complex[Zn(3,4-APT)2(H2 O)4]·8 H2 O(1,3,4-HAPT=4-(5-(pyridin-3-yl)-4 H-1,2,4-triazol-3-yl)benzoic acid)has been prepared and characterized by elemental analysis,X-ray single-crystal diffraction analysis,thermogravimetric analysis and infrared spectrum analysis.Theoretical calculation based on density functional theory(DFT)is also employed to explicate frontier orbitals of 3,4-HAPT.X-ray single-crystal diffraction analysis reveals that 1 belongs to the triclinic system,space group P1 with a=7.5123(3),b=8.6745(3),c=15.2074(6)Å,α=78.469(1),β=87.387(1),γ=65.448(1)°,V=882.42(6)Å,Z=1,D_(c)=1.528 g·cm^(–3),μ=0.780 mm^(–1),M_(r)=812.09,F(000)=424,the final R=0.0401 and wR=0.1136.Zn(II)ion is coordinated by two N atoms from two 3,4-HAPT as well as four O atoms from four coordinated water molecules,forming a 0D motif with distorted octahedral coordinated geometry.The adjacent 0 D units are linked into a 3 D supramolecular structure through hydrogen bonding interaction.In addition,complex 1 exhibits better antifungal activity against Colletotrichum gloeosporioides Penz than the ligand and metal salt by MIC,MBC tests and Kirby-Bauer disc diffusion method which exhibit potential application in the antifungal fields.

Molecular Design and Property Prediction of High Density 4-Nitro-5-(5-nitro-1,2,4-triazol-3-yl)-2H-1,2,3-triazolate Derivatives as the Potential High Energy Explosives

To search for potential energetic materials with large energy density and acceptable thermodynamics and kinetics stability,twelve derivatives of 4-nitro-5-(5-nitro-1,2,4-triazol-3-yl)-2H-1,2,3-triazolate(named A~L)are designed and analyzed by using density functional theory(DFT)calculations at the B3LYP/6-311G**level of theory.The molecular heats of formation(HOF),electronic structures,impact sensitivity(H_(50)),oxygen balance(OB)and density(ρ)are investigated by isodesmic reaction method and physicochemical formulas.Furthermore,the detonation velocity(D)and detonation pressure(P)are calculated to study the detonation performance by Kamlet-Jacobs(K-J)equation.These results show that new molecule J(H_(50)=36.9 cm,ρ=1.90g/cm^(3),Q=1912.46 cal/g,P=37.82 GPa,D=9.22 km/s,OB=0.00),compound A(H_(50)=27.9 cm,ρ=1.93 g/cm^(3),Q=1612.93 cal/g,P=38.90 GPa,D=9.19 km/s)and compound H(H_(50)=37.3 cm,ρ=1.97 g/cm^(3),Q=1505.06cal/g,P=37.20 GPa,D=9.01 km/s)present promising effects that are far better RDX and HMX as the high energy density materials.Our calculations can provide useful information for the molecular synthesis of novel high energy density materials.

Synthesis of N-Aryl-2-(1′,6′-dihydro-6′-pyridazinone-3′-carbonyl) Thiosemicarbazides and Their Related Heterocyclic Compounds

Dihydro-3-hydrozinocarbonyl-6-pyridazinone(compound 2) were prepared from α-ketoglutaric acid and hydrazine hydrate. A series of N-aryl-2-(1′,6′-dihydro-6′-pyridazinone-3′-carbonyl) thiosemicarbazides 3a_3f were synthesized from the reaction of aryl isothiocyanates with compound 2. The terminal compounds 1,3,4-thiadiazole, 1,3,4-oxadiazole and 1,2,4-triazol-5-thione derivatives were cyclized from compounds 3a_3f. Their structures were confirmed by IR, 1H NMR, MS and elemental analyses.

An efficient synthesis of novel benzo[b]pyrido[3',2':4,5]thieno[2,3-e][1,6]naphthy-ridine-8-ones

An efficient method for the synthesis of novel benzo[b]pyrido[3＇,2＇：4,5]thieno[2,3-e][l,6]naphthyridine-8-one derivatives has been developed using a Pictet-Spengler reaction between 4-（3-aminothieno[2,3-b]pyridin-2-yl）quinoline-2-ones,which could be obtained from the alkylation of4-bromomethylquinoline-2-ones with 3-cyanopyridine-2-thione followed by a Thorpe-Ziegler isomerization,and aromatic aldehydes under p-TsOH as catalysis in good yields.

Theoretical Study on the Nitrogen-rich Derivatives Based on 1,2,4-Triazole and 1,2,3-Triazole Rings:an Extended Family of Power Performance Energetic Materials

The geometric and electronic structures of the derivatives of 4-nitro-5-(5-nitroimino-1,2,4-triazol-3-yl)-2H-1,2,3-triazolate(named A~J)are explored employing density functional theory(DFT)calculations at the B3LYP/6-311G^(**)level of theory.Based on the optimized molecular structures,the heats of formation(HOF)are obtained,and the electronic properties,density and molecular sensitivity by characteristic heights(H_(50))are discussed.Besides,the detonation performances(detonation velocity,detonation pressure)are estimated via Kamlet-Jacobs(K-J)formula.Compounds B(H50=29.4 cm,ρ=1.91 g/cm^(3),Q=1563.04 cal/g,P=36.05 GPa,D=8.95 km/s)and H(H_(50)=31.9 cm,ρ=1.80 g/cm^(3),Q=1610.09 cal/g,P=37.31 GPa,D=9.12 km/s)have positive HOFs and remarkable insensitivity and good detonation performance,strongly suggesting them as the acceptable new-type explosive.The initiating power surpasses conventional primary explosives,such as HMX.The outstanding detonation power of compounds B and H contributes to its future prospects as a promising green primary explosive.

Designing energetic covalent organic frameworks for stabilizing high-energy compounds

As an emerging high-energy compound,3-nitro-1,2,4-triazol-5-one(NTO)is used in military explosives and rocket propellants.However,the strong acidic corrosion of NTO,and the high sensitivity and poor thermostability of its salts,severely restrict their practical applications.Therefore,a novel strategy to design and construct energetic covalent organic frameworks(COFs)is proposed in this study.We have successfully prepared a two-dimensional crystalline energetic COF(named ECOF-1)assembled from triaminoguanidine salt,in which NTO anions are trapped in the porous framework via the ionic interaction and hydrogen bonds.The results show that ECOF-1 exhibits superior thermal stability than energetic salt of NTO.It also exhibits insensitivity and excellent heat of detonation of 7,971.71 kJ·kg−1.ECOF-1 greatly inhibits the corrosiveness of NTO.In prospect,energetic COFs are promising as a functional platform to design high-energy and insensitive energetic materials.

Synthesis, Crystal Structure and Thermal Behavior of GZTO·H2O

Guanidimium-4,4-azo-l-hydro-1,2,4-triazol-5-one （GZTO·H2O） was synthesized from 4-amino-1,2,4-triazol- 5-one as a starting material by two-step including oxidation coupling using acid KMnO4 and reaction with （NH2）2C=NHoHNO3 （GN） in KOH solution. The single crystal of the title compound was obtained by slow evapo- ration method at room temperature, and its structure was firstly determined with X-ray single-crystal diffractometer. It is a orthorhombic crystal, space group Pbca with cell dimensions of a = 1.0459（2） nm, b =- 1.3584（3） nm, c= 1.6103（3） nm, a= 90.00（10）°, β=90.00（11）°,γ=90.00（11）°, V=2.2878（8） nm3, Z=8, De= 1.587 gocm-3, F（000） = 1136,/l = 0.132 mm- 1, R1 = 0.0455, wR2 = 0. 1397. The thermal behavior of GZTO·H2O was studied under a non-isothermal condition by DSC-TGA method, and its thermal decomposition process can be divided into three stages, and the first stage is an intense exothermic decomposition process. The second stage and the third stage are slow exothermic decomposition processes. The critical temperature of thermal explosion is 237.74℃.

An efficient synthesis of novel pyridothieno-fused thiazolo[3,2-α]pyrimidinones via Pictet–Spengler reaction

An efficient method for the synthesis of novel pyrido[3＇＇,2＇＇：4＇,5＇]thieno[3＇,2＇：2,3]pyrido [4,5：d][1,3]thiazolo[3,2-a]pyrimidine-4-one derivatives（5） has been developed using a Pictet–Spengler reaction between 2-（3-aminothieno[2,3-b]pyridin-2-yl）thiazolo[3,2-a] pyrimidin-5-one（3）, which could be obtained from the condensation of 7-（chloromethyl）-5H-thiazolo[3,2-a]pyrimidin-5-one（1） with3-cyanopyridine-2-thione（2） via Thorpe–Ziegler isomerization, and aromatic aldehydes under NH2SO3 H as catalysis in good yields.