Iron(Ⅲ) phthalocyanine chloride-catalyzed oxidation–aromatization of α,β-unsaturated ketones with hydrazine hydrate: Synthesis of 3,5-disubstituted 1H-pyrazoles

We have developed an iron（III） phthalocyanine chloride‐catalyzed oxidation–aromatization ofα,β‐unsaturated ketones with hydrazine hydrate. Various 3,5‐disubstituted 1H‐pyrazoles were obtained in good to excellent yields. This method offers several advantages, including room‐tem‐perature conditions, short reaction time, high yields, simple work‐up procedure, and use of air as an oxidant. The catalyst can be recovered and reused five times without loss of activity.

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.

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, X-ray Crystallographic Analysis and Bioactivities of α-Aminophosphonates Featuring Pyrazole and Fluorine Moieties

A series of novel -aminophosphonates containing pyrazole and fluorine moieties was designed and synthesized through ultrasonic-assisted condensation and solvent-free addition reactions. Their structures were verified by IR, ^1H NMR, ^13C NMR and elemental analysis. The crystal structure of diethyl[（4-cyano-1H-pyrazol-3-ylamino）（3,5-difluorophenyl）methyl]phosphonate（4a, C15H17F2N4O3P） was determined by single-crystal X-ray diffraction. Compound 4a crystallizes in the triclinic system, space group P1 with a = 8.381（3）, b = 10.103（5）, c = 11.268（3） A, α= 83.772（19）, β= 74.726（19）, γ= 70.964（18）, V = 869.9（6） 3, Mr = 370.30, Dc = 1.414 g/cm^3, Z = 2, F（000） = 384, = 0.200 mm^-1, MoKa radiation（ = 0.71073 ）, the final R = 0.0487 and w R = 0.0823 for 1582 observed reflections with I 〉 2（I）. X-ray diffraction analysis reveals that there are two planes in 4a, and the dihedral angle is 71.51°. Two intermolecular hydrogen bonds and a face-to-face … stacking interaction are observed in the crystal structure. The compounds were evaluated for their antifungal, antiviral and antitumor activities, respectively. Among them, 4b, 4c, 4g and 4h exhibit good activities on Sclerotium rolfsii Sacc at 200 μg/m L, while 4b, 4c, 4f and 4g possess good anti-TMV activities at 500 μg/m L. Unfortunately, all of the compounds showed weak antitumor activities.

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） ?, β = 97.632（6）°, V = 1470.8（11） ?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）.

Bovine serum albumin:An efficient and green biocatalyst for the one-pot four-component synthesis of pyrano[2,3-c]pyrazoles

The use of biocatalysts is attracting an increasing amount of attention in chemical catalysis.Here,we have shown that bovine serum albumin（BSA）,a ubiquitous,inexpensive,non-enzymatic transport protein,can serve as an efficient,retrievable catalyst in the one-pot four-component reaction of aryl aldehydes,malononitrile,hydrazine hydrate,and ethyl acetoacetate for the synthesis of pyrano[2,3-c]pyrazoles under mild reaction conditions.The BSA biocatalyst also displayed a high catalytic affinity for acyclic/cyclic ketones to yield the corresponding pyrano[2,3-c]pyrazoles or their spirocyclic variants.The BSA could be used for at least five cycles without serious loss of catalytic activity.This novel,efficient protocol has the merits of high yield,operational simplicity,and a relatively benign environmental impact.Moreover,the method extends the promiscuity of BSA as a biocatalyst.

A New Approach to Ethyl 1-Aroyl/Aroylmethyl-5-methyl-3- methylthiopyrazole-4-carboxylates: High Regioselectivity in Alkylation and Acylation Reactions between N-1 and N-2 of a Pyrazole Derivative

Two series, totalizing twelve, of new compounds, ethyl 1-aroyl/aroylmethyl-5-methyl-3- methylthiopyrazole-4-carboxylates 5/6, have been synthesized via highly regioselective acylation and alkylation of ethyl 3-methyl-5-methylthio-1H- pyrazole-4-carboxylate 2a with aroyl chloride 3 and alpha-tosyloxysubstitutedacetophenones 4. Unexpected structures of the product have been unambiguously determined by both X-ray crystallographic analysis and 2D NMR.

Synthesis, Crystal Structure, Theoretical Studies and Sensitive Response toward Fe^(3+) of a Novel Tripyrazole Derivative Ligand

A novel pyrazole derivative ligand, BTA（BTA = bis-（4-ethoxy-phenyl）-[4-（tripyrazol-1-yl-methyl）-phenyl]-amine）, was synthesized and fully characterized by 1H-NMR, MALDI-TOF-MS spectra and single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1, with a = 11.827（1）, b = 16.000（2）, c = 16.527（2）A, α = 108.510（1）, β = 91.116（5）, γ = 101.734（1）°, V = 2894.5（6） A3, Z = 1, Dc = 1.262 g/m^3, F（000） = 1162, Μr = 545.63, μ = 0.083 mm-1, the final R = 0.0728 and w R = 0.2213 for 7541 observed reflections with I 〉 2（I）. The structural analysis revealed that three pyrazole units are attached to the same carbon atom connected with bis-（4-ethoxy-phenyl）-phenyl-amine group. UV-vis spectral features of the ligand in various solutions were explained by time dependent density functional theory（TD-DFT）. It was also found that the ligand（BTA） exhibits an exclusively selective and sensitive response toward Fe3＋ using UV-vis spectroscopic method.

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 Cytotoxic Activity of Novel Tetrahydrocurcumin Derivatives Bearing Pyrazole Moiety

Tetrahydrocurcumin(THC)is a major metabolite of curcumin and plays an important role in curcumin-induced biological effects.THC is a promising preventive and chemotherapeutic agent for cancer.A series of new pyrazole derivatives of THC have been synthesized as potent anticancer agents.Direct condensation of THC with various substituted hydrazines leads to new pyrazole derivatives of THC(1-18).The prepared compounds have been evaluated via in vitro MTT(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)assay for their cell proliferation-inhibitory activity against human lung adenocarcinoma(A549),human cervical carcinoma(HeLa)and human breast carcinoma(MCF-7)cells.Most derivatives show significantly higher anticancer activity against all three tested cancer cell lines than the parent compound THC.Several compounds(7,8,12,13 and 15)display promising anticancer activity against MCF-7 cell line with IC50 values ranging from 5.8 to 9.3 iM.The most active compound(8)is substituted with 4-bromophenyl group at the pyrazole ring and inhibits the growth of all three tested cancer cell lines with an IC50 values of(8.0 iM,A549),(9.8 iM,HeLa)and(5.8 iM,MCF-7).The obtained compounds can be a good starting point for the development of new lead molecules in the fight against cancer.