Key Intermediates: A Simple and Highly Selective Synthesis of 5-<i>Amino</i>-1-<i>aryl</i>-1<i>H</i>-<i>pyrazole</i>-4-<i>carbonitriles</i>for Applications in the Crop Protection

A series of six pyrazoles was synthesized by Michael-type addition reaction. The molecules 5-amino-1-aryl-1H-pyrazole-4-carbonitrile (3a-f) were synthesized from (ethoxymethylene)malo-nonitrile (1) and fluorinated and non-fluorinated aryl hydrazines (2a-f) using ethanol and fluorinated ethanol as solvents at reflux. An excellent regio-selectivity was found when pyrazole derivatives were formed as an exclusive product. No other regioisomer or uncyclised hydrazide was observed. Their structures were confirmed by spectroscopy data (1H, 13C, 19F, COSY (correlation spectroscopy), HSQC (heteronuclear single-quantum correlation spectroscopy) and HMBC (heteronuclear multiple-bond correlation spectroscopy);MS (mass-spectrometry). The yields ranged from good to excellent (47% - 93%) under mild reaction conditions. It would indicate a high selectivity in the one-step work procedure. These products (3a-f) and derivatives have a potential academic and industrial use as key intermediates, in special, for application in crop protection.

A Convenient Synthesis of Pyrazolylpyrazoles Using α-Oxo Ketene S,S- and N,S-Acetals

Substituted pyrazolylpyrazoles were synthesized through the reaction of hydrazine hydrate and α-oxo-(3, 5-dimethyl-1 H-pyrazole-1-ly)ketene S, S- and N,S-Acetals which were obtained from α-oxo-(3,5-dimethyl-1 H-pyrazole-1-yl) acetophenone. Pyrazolylpyrazole was also prepared via α-oxo ketene N,O-acetal by way of ring chain transformation.

Synthesis, Crystal Structure, Docking and Antifungal Activity of a New Pyrazole Acylurea Compound

The title compound N-（（3,5-dimethylphenyl）carbamoyl）-1-methyl-3-（trifluoromethyl）-1 H-pyrazole-4-carboxamide（C（15）H（15）F3N4O2） was synthesized, and its structure was confirmed by 1 H NMR, H RMS and X-ray diffraction. It crystallizes in the triclinic system, space group P1 with a = 11.7147（5）, b = 11.7935（5）, c = 13.6620（5） A, α = 69.755（7）°, β = 66.182（6）°, γ = 72.100（7）°, Dc = 1.423 g/cm^3, Z = 4, V = 1588.88（11） A^3, the final R = 0.0347 and wR = 0.1005 for 7171 observed reflections with I 〉 2σ（I）. The preliminary biological test showed that the title compound has antifungal activities against Fusarium oxysporum, Pseudomonas syringae, Corynespora mazei and Botrytis cinerea at 100 μg/mL as 5.19%, 53.50%, 88.55% and 70.62%, respectively. The docking results indicated the hydrogen bonds formed between the compound and SHD.

Syntheses of 1,3,4-Thia(oxa)diazole-substituted Pyrazole Derivatives and Their Fungicidal Activities

A series of 1,3,4-oxadiazole or 1,3,4-thiadiazole-substituted pyrazole derivatives were synthesized from 4-pyrazole formhydrazide; their biological activities were studied. The structures of all the new compounds were confirmed by means of spectroscopic methods and microanalyses. The preliminary bioassay results indicate that some compounds of them have a good fungicidal activity against Phoma asparagi and Physalospora piricola Nose.

Synthesis and Crystal Structure of Ethyl 1-(2-bromoethyl)-3-(4-meth-oxyphenyl)-1H-pyrazole-5-carboxylate

The title compound ethyl 1-（2-bromoethyl）-3-（4-methoxyphenyl）-1H-pyrazole-5-carboxylate 1 has been synthesized and structurally characterized by single-crystal X-ray diffraction.The crystal is of monoclinic（C15H17BrN2O3,Mr = 353.22）,space group C21 with a = 24.691（7）,b = 6.7678（17）,c = 17.884（5） ,β = 97.184（5）o,V = 2965.1（13） 3,Z = 8,Dc = 1.583 g.cm-3,F（000） = 1440,μ = 2.784 mm-1,the final R = 0.0260 and wR = 0.0596 for 2684 observed reflections with I 2σ（I）.All the carbon atoms in the molecule are nearly coplanar except C（15）,with a large conjugated system among the carbonyl group,pyrazole ring and the benzene ring.Three non-classical intermolecular hydrogen bonds help to stabilize the crystal lattice.The regioselectivity was rationalized based on the coordination of potassium ion with the N-anion and the carbonyl oxygen atom.

Novel dihydropyrazole derivatives linked with multi(hetero)aromatic ring:Synthesis and antibacterial activity

Eight novel heterocycle-substituted dihydropyrazole derivatives were synthesized and characterized by ESI-MS, ^1H NMR and ^13C NMR. All of the compounds have been screened for their antibacterial potential in vitro against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The results show that compounds 9b, 9g and 9h displayed significant activity with MIC values in the range of 0.39-1.562 μlmL against B. subtilis.

Synthesis, Crystal Structure and Fungicidal Activity of 3-(Difluoromethyl)-1-methyl-N-((2-(trifluoromethyl)phenyl) carbamoyl)-1H-pyrazole-4-carboxamide

The title compound 3-(difluoromethyl)-1-methyl-N-((2-(trifluoromethyl)phenyl)-carbamoyl)-1 H-pyrazole-4-carboxamide(C14 H11 F5 N4 O2) was synthesized, and its structure was confirmed by 1 H NMR, H RMS and X-ray diffraction. It crystallizes in monoclinic system, space group P21/n with a = 6.994(3), b = 13.860(6), c = 15.308(7)A,β= 97.632(6)°, V = 1470.8(11) A^3,Z = 4, the final R = 0.0692 and wR = 0.2108 for 3989 observed reflections with Ⅰ> 2σ(Ⅰ). The preliminary biological test shows that the title compound has moderate fungicidal activities against Pseudomonas syringae.

Microwave-assisted Syntheses,Structures and Bioactivities of α-Aminophosphonates Containing Pyrazole and 2-Hydroxybenzyl Units

Using 3-amino-4-cyanopyrazole, salicylaldehyde and dialkylphosphite as materials, a series of a-aminophosphonates containing pyrazole and 2-hydroxybenzyl units were synthesized under microwave irradiation without solvents and catalysts. The structures of the compounds were verified by IR, 1H NMR, J3C NMR and elemental analysis. The crystal structure of diisobutyl {a-[3- （4-cyano-lH-pyrazol）amino）]-N-（2-hydroxylbenzyl）}phosphonate （4d, C19H27N404P） was deter- mined by single-crystal X-ray diffraction. Compound 4d crystallizes in the orthorhombic system, space group Pbcn with a = 17.329（4）, b = 20.091（5）, c = 12.433（3）/k, V = 4328.7（17） A3, M,. = 406.42, Dc = 1.247 g/cm3, Z = 8, F（000） = 1728,μ = 0.158 mm-1, MoKa radiation （2 = 0.71073 A）, the final R = 0.064 and wR = 0.0169 for observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that two planes lie in 4d, and the dihedral angle is 85.76°. Intermolecular O（1）-H（1B）-O（2）, N（1）-H（1）-N（4）, N（3）-H（3）.-.N（2） and N（3）-H（3）...O（1） hydrogen bonds are found in the structure. All the compounds were evaluated for their antiviral and antitumor activities respectively. Among them, 4d and 4e showed moderate anti-TMV activities at 500 gg/mL, and 4e possessed excellent antitumor activity against PC3 cells at 10 gmol/L.

Syntheses,Crystal Structures and Antibacterial Activities of 5-Chloro-3-methyl-1-phenyl-1H-pyrazole-4-carboxylic Acid and Its Copper(Ⅱ) Compound

The title compounds 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carboxylic acid（C11H9Cl N2O2, HL）（1） and [Cu（L）2（H2O）]（2） were prepared and structurally characterized by elemental analysis, IR and single-crystal X-ray diffraction. Compound 1（C11H9Cl N2O2） crystallizes in the monoclinic system, space group P21/n with a = 7.249（3）, b = 20.515（10）, c = 7.249（3）,β= 96.30°, V = 1071.6（9） ？3, Z = 4, Mr = 236.65, Dc = 1.467 g/cm3, F（000） = 488, GOOF = 1.029, μ= 0.341 mm-1, the final R = 0.0736 and w R = 0.1966 for 1500 observed reflections with I 〉 2σ（I）. Compound 2（C22H18Cl2Cu N4O5） crystallizes in the monoclinic system, space group P21/c with a = 7.2931（6）, b = 24.548（2）, c = 13.2726（11）, β= 99.4040（10）°, V = 2344.2（3） ？3, Z = 4, Mr = 552.84, Dc = 1.566 g/cm3, F（000） = 1124, GOOF = 1.050, μ= 1.201 mm-1, the final R = 0.0376 and w R = 0.1000 for 3626 observed reflections with I 〉 2σ（I）. 1 and 2 are connected through hydrogen bonding interactions to generate 2D and 3D supramolecular structures, respectively. Moreover, the preliminary antibacterial activities of 1 and 2 against the gram positive bacteria（S. aureus, C. albicans and B. subtilis） and gram negative bacteria（E. coli and P. aeruginosa） have been tested by using the microdilution method, and the results indicate that 2 is more active than 1 against the tested bacteria.

A Two-dimensional Metallic Oxide Constructed from Molybdenum Clusters and Ag(Ⅰ)-[3-(2-pyridyl)-pyrazole] Cationic Coordination Components

A new polyoxomolybdate compound [Ag 3 （HL） 4 ]（PMo 12 O 40）] 1 （HL=3-（2-pyridyl）pyrazole） has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction,elemental analyses,TG and IR spectroscopy.The compound crystallizes in triclinic,space group P1 with a=10.375（3）,b=12.076（3）,c=13.196（4）,α=84.170（4）,β=71.961（3）,γ=86.326（4）°,V=1563.1（7）3,C 32 H 28 Ag 3 Mo 12 N 12 O 40 P,M r=2726.52,D c=2.897 g/cm 3,μ（MoKα）=3.366 mm 1,F（000）=1284,Z=1,the final R=0.0587 and wR=0.1312 for 4139 observed reflections （I 2σ（Ⅰ））.X-ray diffraction analyses reveal that the PMo 12 O 40 3clusters in compound 1 are linked by four Ag 3 （HL） 4 3＋ units via the terminal oxygen atoms to form a two-dimensional architecture.The symmetrical unit of Ag 3 （HL） 4 3＋ exhibits two distinct Ag（Ⅰ） environments：a two-coordinate {AgN 2 } site and a five-coordinate {AgN 3 O 2 } site which links to two molybdate clusters.

Synthesis and Biological Activity of New Pyrethroid Acid Oxime-esters Containing Pyrazole Ring

A series of compounds containing oxime-ester linkage and pyrazole ring(in place of the ester linkage and the alcohol moiety in pyrethroid ester) was designed and synthesized. The structures of all the compounds prepared were confirmed by 1H NMR and MS spectroscopy as well as elemental analyses. The bioassay data of those compounds against tobacco mosaic virus(TMV), cucumber mosaic virus(CMV), potato virus X(PVX) and potato virus Y(PVY) were presented. Among them compound 6i was found to possess significant plant antiviral activities. But all the compounds showed low insecticidal and acaricidal activities.

Synthesis and Crystal Structure of Dimethyl-3-(4-bromophenyl)-1-phenyl-4,5-dihydro-1H-pyrazole-4,5-dicarboxylate

The title compound （C19H17BrN2O4） was synthesized via a one-pot procedure starting from 4-bromobenzaldehyde, dimethyl acetylenedicarboxylate （DMAD） and phenylhydrazine with pyridine as the catalyst. Its structure was determined by single-crystal X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P21/c with a = 11.115（3）, b = 8.090（2）, c = 20.211（5） , β = 97.032（5）°, V = 1803.7（8） 3, Z = 4, Mr = 417.25, Dc = 1.536 g/cm3, μ = 2.306 mm-1, F（000） = 852, the final R = 0.0403 and wR = 0.0895 for 2215 observed reflections with I 2σ（I）.

Synthesis,Crystal Structure and Antifungal Activities of 3-Methyl-1-(4-methylphenyl)-4-(N-4-trifluoromethylphenyl)-aminomethyl-5-(4-methoxyphenylthio)-1H-pyrazole

The title compound 3-methyl-l-（4-methylphenyl）-4-（N-4-trifluoromethylphenyl） aminomethyl-5-（4-methoxyphenylthio）-lH-pyrazole has been synthesized via a four-step reaction and characterized by IR, 1H NMR, elemental analysis and X-ray crystallography. The compound crystallizes in monoclinic, space group P21/c with a = 8.7170（15）, b = 18.355（3）, c = 15.292（3） A, fl = 103.445（3）°, V= 2379.7（7） A3, Dc = 1.350 g/cm3, Z = 4, p = 0.184, F（000） = 1008, and the final R = 0.0491 and wR = 0.1339 for 4160 observed reflections （I 〉 2a（/））. The results demonstrate that there is a face-to-face π-π stacking interaction between one benzene ring （C（19）-C（24）） and another （C（I 3）-C（! 8）） at a plane-plane distance of 3.3539 A. The ring normal and vector between the ring centroids form an angle of 18.2° up to the centroid-to-centroid distance of 3.5273 A. The crystal structure is stabilized by the intermolecular hydrogen bond of N（3）-H（3A）...N（2） （symmetry code： A -x＋l, -y＋l, -z）. The preliminary biological test shows that the title compound has a moderate antifungal activity.

Synthesis and Crystal Structureof Ethyl 5-Amino-1-[(5′-methyl-1′-t-butyl-4′-pyrazolyl)carbonyl]-3-methylthio-1H-pyrazole-4-carboxylate

The title compound, ethyl 5-amino-1-[(5?-methyl-1?-t-butyl-4?-pyrazolyl)carbonyl] -3-methylthio-1H-pyrazole-4-carboxylate 5, has been synthesized by the treatment of 4 with ethyl 2-cyano-3,3-dimethylthioacrylate, and its crystal structure was determined by X-ray diffraction method. The crystal belongs to monoclinic, space group P21/c with a = 12.194(4), b = 12.909(4), c = 11.607(4) ?, β = 90.183(5)°, V = 1827.2(10) ?3, Mr = 365.45, Z = 4, Dc = 1.328 g/cm3, μ = 0.203 mm-1, F(000) = 776, R = 0.0586 and wR = 0.1558. Preliminary bioassays indicated that the title compound shows fungicidal and plant growth regulation activities.

Syntheses, Crystal Structures and Antifungal Activities of Two Compounds Containing Pyrazole and Pyrethroid Units

Compounds 1 （C15H17C1F3N303, Mr = 379） and 2 （C14H14C1F3N4OS, Mr = 378） have been synthesized and their crystal structures were determined by single-crystal X-ray diffraction. Crystal 1 belongs to the triclinic system, space group P1 with a = 6.0223（19）, b = 9.324（3）, c = 15.936（5） A, a = 80.687（5）, β= 87.289（5）, ）, = 86.097（5）°, V= 880.4（5） A3, Z = 2, Dc = 1.433 g/cm3,μ（MoKa） = 0.266 mm^-1, F（000） = 392, R = 0.0861 and wR = 0.1999 for 2022 observed reflections with I 〉 2o（/）. Crystal 2 belongs to the triclinic system, space group PI with a = 7.7029（15）, b = 8.3371（16）, c = 14.410（3） A, a = 100.672（3）, β= 103.168（3）, ？ = 98.726（3）°, V = 876.1（3） A3, Z = 2, Dc= 1.451 g/cm^3,μ（MoKa） = 0.379 mm^-1, F（000） = 388, R = 0.0672 and wR = 0.2105 for 2725 observed reflections with I 〉 2σ（I）. Although the two compounds are similar with the same pyrazole and pyrethroid units, X-ray analysis reveals that their structures are completely different.

Synthesis and Crystal Structure of a Polyoxomolybdate Framework Modified by Mn-L Units(L=3-(2-Pyridyl)pyrazole)

A new polyoxomolybdate compound,namely {[MnII（L）（4,4？-Hbipy）（H2O）2]2 [Mo5O15（PO4）2]}.2H2O 1（L = 3-（2-pyridyl）pyrazole,4,4＇-Hbipy = protonated 4,4＇-bipyridine）,was designed and synthesized under hydrothermal conditions.Single-crystal X-ray diffraction analysis result reveals that the [Mo5O15（PO4）2]6-cluster in compound 1 links to two MnII cations via the oxygen of PO43-,which is further coordinated by one 3-（2-pyridyl）pyrazole,one 4,4＇-Hbipyridine,and two water molecules.

Synthesis,Crystal Structure and Insecticidal Activity of N-(pyridin-2-ylmethyl)-1-phenyl-1,4,5,6,7,8-hexahydrocyclohepta[c]pyrazole-3-carboxamide

The title compound N-（pyridin-2-ylmethyl）- 1-phenyl- 1,4,5,6,7,8-hexahydrocy-clohepta[c]pyrazole-3-carboxamide 5 （C21I-I22N40, Mr = 346.42） has been synthesized andstructurally characterized by IR, 1H NMR, 13C NMR, H RMS and single-crystal X-raydiffraction. The crystal crystallizes in monoclinic system, space group P21/n with a = 8.668（2）,b = 22.236（4）, c = 9.539（2） A, β = 108.68（3）°, V = 1786.4（7）/k3, Z = 4, Dx= 1.288 g/cm3,F（000） = 736,μ（MoKa） = 0.649 mm^-1, the final R = 0.0354 and wR = 0.0933 with 3234observed reflections with I 〉 2σ（/）. The benzene and pyrazole rings are nearly coplanar with adihedral angle of 50.977（46）°. The dihedral angle between the central pyrazole and pyridinerings is 11.688（46）°. No classical hydrogen bonds were found in the molecules. Two adjacentmolecules in crystal packing of compound 5 were linked by two intramolecularhydrogen-bonding interactions C（15）-H（15）…O（1） to generate a stable structure. Compound 5had weak insecticidal activity against the diamondback moth （Plutella xylostella）, butexhibited good activity against cotton bollworm （Helicoverpa armigera）.

A Two-dimensional Metallic Oxide Constructed from Molybdenum Clusters and Zn(Ⅱ)-[3-(2-pyridyl)pyrazole] Cationic Coordination Components

A new polyoxomolybdate compound [Zn（HL）2（Mo8O26）（4,4＇-Bipy）]·（4,4＇-Bipy） （HL = 3-（2-pyridyl）pyrazole, 4,4＇-Bipy = 4,4＇-bipyridine） 1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analyses, TG and IR spectroscopy. The compound crystallizes in monoclinic, space group C2/c with a = 18.060（4）, b = 13.870（3）, c = 19.360（4） A, β = 93.50（3）°, V = 4840.5（17） 3, C36H30Mo8N10O26Zn, Mr = 1851.59, Dc = 2.541 g/cm^3, μ（MoKα） = 2.589 mm·1, F（000） = 3560, Z = 4, the final R = 0.0328 and wR = 0.0870 for 4005 observed reflections （I 〉 2σ（I））. X-ray diffraction analyses reveal that compound 1 is constructed from Mo8O264-units linked by Zn（HL）22＋ and 4,4＇-Bipy. Mo8O264-is connected by Zn（HL）2^2＋ via terminal oxygen atoms along the [010] axis forming chains, which are further linked by 4,4＇-Bipy along the [001] axis forming a two-dimensional network structure.

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.