Syntheses and crystal structures of four new organotin complexes with Schiff bases containing triazole

Four new organotin complexes, namely [(Bu₂Sn)₂O(EtO)(L1)]₂ (1), [(Bu₂Sn)₂O(EtO)(L2)]₂ (2), [(Bu₂Sn)₂O(EtO)(L3)]₂ (3) and [Ph₃Sn(L4)] · 0.5H₂O (4), were obtained by reactions of Bu₂SnO and Ph₃SnOH with 4-phenylideneamino-3-methyl-1,2,4-triazole-5-thione (HL1), 4-furfuralideneamino-3-methyl-1,2,4-triazole-5-thione (HL2), 4-(2-thienylideneamino)-3-ethyl-1,2,4 -triazole-5-thione (HL3) and 4-(3,5-di-t-butylsalicylideneamino)-3-ethyl-1,2,4-triazole-5-thione (HL4). Compounds 1-4 were characterized by elemental analysis, IR spectra and their structures were determined by single-crystal X-ray diffraction methods. Complexes 1-3 show similar structures containing a Sn₄O₄ ladder skeleton in which each of the exo tin atoms is bonded to the N atom of a corresponding thione-form deprotonated ligand. Complex 4 shows a mononuclear structure in which the tin atom of triphenyltin group is coordinated by the S atom of a thiol-form L4⁻ anion.     

Synthesis,antifungal and insecticidal activity of novel [1,2,4]triazolo[4,3-<Emphasis Type="Italic">a</Emphasis>]pyridine derivatives containing a sulfide substructure

A series of [1,2,4]triazolo[4,3-a]pyridine derivatives bearing a sulfide substructure was designed, synthesized and characterized via ¹H·NMR, ¹³C·NMR, IR and elemental analyses. Bioassay Results indicated some of the derivatives displayed good fungicidal activity on Rhizoctonia cerealis, moderated insecticidal activity against Plutella xylostella and good insecticidal activity on Helicoverpa armigera. The inhibitory effects of compounds 4g and 4u against Rhizotonia cerealis were 70.9% at 50 μg mL^?1; the IC₅₀ values of compounds 4d and 4s against Plutella xylostella were 43.87 and 50.75 μg mL^?1, respectively. And the IC₅₀ values of compounds 4d, 4q, and 4s on Helicoverpa armigera were 58.3, 77.14 and 65.31 μg mL^?1, respectively, which were better than that of commercial chlorpyrifos (103.77 μg mL^?1).     

Synthesis,characterization and antitumor activity of palladium(II) complexes of imidazolidine-2-thione

Complexes of the type cis-[PdX₂(imzt)(PPh₃)] {imzt = imidazolidine-2-thione; PPh₃ = triphenylphosphine; X = Cl (1), Br (2), I (3), SCN (4)} have been synthesized and characterized by elemental analyses, molar conductance, IR and ¹H NMR spectroscopies. The complex 1·MeOH was obtained from the reaction of [PdCl₂(CH₃CN)₂], imidazolidine-2-thione and triphenylphosphine in CHCl₃/CH₃OH. Complexes 2·MeOH, 3 and 4 were prepared by metathesis of the chlorido ligands in 1 with bromide, iodide and thiocyanate, respectively. Elemental analyses showed good agreement with the expected mononuclear compositions, while the molar conductivities of the complexes in DMF were consistent with their nonelectrolytic nature. NMR spectra confirmed coordination of the imidazolidine-2-thione and triphenylphosphine ligands. Single-crystal X-ray diffraction determination of 1·CH₃OH showed that the coordination geometry around Pd^II is nearly square planar, with the chlorido ligands in a cis configuration. All four complexes have been tested in vitro by XTT assay for their cytotoxicity against human glioblastoma cell line (U87MG). The binding of 1 with guanosine was studied by ¹H NMR spectroscopy, revealing that the coordination takes place via N7.     

Synthesis and in vitro cytotoxic evaluation of some novel hexahydroquinoline derivatives containing benzofuran moiety

A series of new ethyl 4-(2-(benzofuran-2-yl)-4-substituted-1,4,5,6,7,8-hexahydroquinolin-1-yl)-benzoate 3a–c was synthesized by Michael condensation of benzofuran chalcones 1a–c and cyclohexanone to give 2-(2-benzofuranyl)-4-substituted-5,6,7,8-tetrahydro-4-H -chromene 2a–c, followed by reaction of the latter with ethyl 4-aminobenzoate. Condensation of 3a–c with different amines afforded the corresponding amides 4a–e. On the other hand, upon treatment compounds 3a–c with hydrazine hydrate gave the benzohydrazide derivatives 5a–c. The reaction of compounds 5a–c with different thio/isocyanate gave the corresponding thiosemicarbazide and semicarbazide derivatives 6a–c. Meanwhile compounds 5a–c were reacted with ethyl cyanoacetate and different β-dicarbonyl compounds such as acetyl acetone, ethyl acetoacetate, and diethyl malonate to afford pyrazolyl derivatives 7a, b; 8a, b; 9a, b; and 10a–c, respectively. Moreover, 5a–c were reacted with carbon disulfide to synthesize the corresponding oxadiazolyl derivatives 11a–c, while their condensation with different aromatic aldehydes gave the corresponding Schiff bases 12a–d. Cytotoxic evaluation of some of the newly synthesized compounds against human hepatocellular carcinoma cell lines (HepG-2) revealed that the tested compounds produce promising inhibitory effect against the growth of HepG-2 cells with IC₅₀ values ranged from 11.9 to 19.3 µg/mL.     

Design,Synthesis, and Cytotoxicity of Semisynthetic Betulinic Acid-1,2,4-Oxadiazole Amide Derivatives

Biological activity of betulinic acid derivatives containing a 1,2,4-oxadiazole ring prompted us to synthesize betulinic acid-1,2,4-oxadiazole amide derivatives 14–25 starting with the amide coupling reaction of betulinic acid 1 and (3-aryl-1,2,4-oxadiazol-5-yl)methanamines 2–13. The products were tested for cytotoxicity on three human cancer cell lines in vitro. All tested compounds demonstrated high activity. The structures of the synthesized compounds were elucidated from IR, NMR and mass spectra.     

Cobalt(III) complexes with biguanide derivatives: Synthesis,structures, and antiviral activity

Three Co(III) complexes with biguanide derivatives [Co(NH₂C(=NH)NHC(=NH)NR¹R²)₃]Cl₃ (R¹R² = Me₂ (I), Et₂ (II), and H^sBu (III)) were obtained and characterized by elemental analysis, IR spectroscopy, and electronic absorption spectroscopy. Structure III was confirmed by X-ray diffraction (CIF file CCDC no. 1401783). Complexes I–III and [M(SC(NH₂)₂)₄]Cl₂ (M = Pd, Pt, and [Co(En)₃]Cl₃) were tested for in vitro antiviral activity against the A/California/07/09 (H1N1pdm09) influenza virus. The best results were achieved with complex III and both thiourea complexes.     

Directed assembly of cobalt(II) 1-H-indazole-3-carboxylic acid coordination networks by bipyridine and its derivatives: structural versatility,electrochemical properties,and antifungal activity

This paper describes the hydrothermal synthesis, full characterization, and architectural diversity of three intriguingly bioactive cobalt–organic frameworks, namely, 3D [Co(HL ^? )₂(BPY)] _n ·4nH₂O (1), 2D [Co(HL ^? )₂(BPE)] _n (2), and 2D [Co(HL ^? )₂(DPP)] _n (3) coordination polymers, synthesized through a mixed ligand strategy using H ₂ L (1-H-indazole-3-carboxylic acid) as a main structural block and the flexible bipyridine and its derivatives (BPY = 4,4′-bipydine, BPE = 1,2-bis(4-pyridyl)ethane, DPP = 1,3-bis(4-pyridyl)propane) as auxiliary ligand sources. Complexes 1–3 were isolated as air stable and slightly soluble crystalline solids and characterized using elemental analysis, FT-IR, electrochemical technique, thermogravimetric analysis, powder X-ray diffractometer, and single-crystal X-ray crystallography. The bipyridine derivatives played key roles in defining the structural space group and dimensionality feature of the obtained networks. The abundant H-bonding and π–π stacking interactions in complexes 1–3 gave rise to their intricate metal–organic structures of 3D (1), 2D (2), and 2D (3). In addition, the solutions of complexes 1–3 showed profound antifungal activities against the selected strain of Colletotrichum musae compared with the controlled group using benomyl as a traditional agrochemical fungicide.     

Synthesis and anticancer activities of 1,4-phenylene-bis-<Emphasis Type="Italic">N</Emphasis>-acetyl- and <Emphasis Type="Italic">N</Emphasis>-phenylpyrazoline derivatives

Novel 1,4-phenylene-bis-N-acetyl- (3a–h) and bis-N-phenylpyrazoline derivatives (4a–h) were obtained by addition of hydrazine hydrate and phenylhydrazine to bis-chalcone derivatives (1a–h) in acetic acid and acetic acid/ethanol for 4 and 8 h in reflux conditions, respectively. The structures of the obtained bis-N-acetylpyrazoline and bis-N-phenylpyrazoline derivatives were characterized by nuclear magnetic resonance (NMR) and infrared (IR) spectroscopic methods and elemental analysis. Compounds 3a–h and 4a–h were investigated to evaluate their anticancer activities against C6 (rat brain tumor cells) and HeLa (human uterus carcinoma) in vitro using a dose-dependent assay from 5 to 100 μM with 5-fluorouracil (5-FU) as standard anticancer drug. Compound 3a showed higher cell-selective activity compared with 5-FU against HeLa cells. Compounds 3a–h (except 3d) were shown to have better activities than 5-FU against both cells, particularly at high concentration. Compound 4c showed higher cell-selective activity compared with 5-FU against C6 cells. Compound 3a may be particularly promising as an anticancer drug against HeLa cells.     

Synthesis and antimicrobial activity of novel fused [1,2,4]triazino[5,6-<Emphasis Type="Italic">b</Emphasis>]indole derivatives

Synthesis of new fused systems of triazino[5,6-b]indole starting with preparation of 3-amino[1,2,4]-triazino[5,6-b]indole 1 by reaction of isatin with 2-aminoguanidinium carbonate in boiling acetic acid is presented [1]. Intermediate compound 1 reacted with aldehyde, ethyl chloroformate, triethyl orthoformate, and ninhydrine and gave new heterotetracyclic nitrogen systems, such as 3-(N ²-guanidinylimino)indole-2(1H)-one 2, 3-(N-ethoxycarbonylamino)-4H-[1,2,4]triazino[5,6-b]indole 3, 3-(N-ethoxymethyleneamino)-4H-[1,2,4]-triazino[5,6-b]indole 4, 3-(hydrazinothiocarbonylamino)-4H-[1,2,4]triazino[5,6-b]indole 5, respectively. N-(1,3-dioxoindene-2-ylidene)-4H-[1,2,4]triazino[5,6-b]indol-3-amine 6 was synthesized by reaction of compound 1 with aldehyde, ethyl chloroformate, triethyl orthoformate, and ninhydrine. New fused indole systems, pyrimido[2′,1′:3,4][1,2,4]triazino[5,6-b]indol-3(4H)-one 8, 9, 11, 12 and 1H-imidazo[2′,1′:3,4][1,2,4]triazino-[5,6-b]indol-2(3H)-one 10, were synthesized in the reaction of the intermediate 1 with bifunctional compounds. Structures of the products were elucidated from their elemental analysis and spectral data (IR, ¹H and ¹³C NMR and mass spectra). Antimicrobial activity of some synthesized compounds was tested.     

Synthesis of novel 5,6,7,8,9,10-hexahydropyrimido[4,5-b]quinoline derivatives for antimicrobial and anti-oxidant evaluation

Because of the well-known chemotherapeutic activity of pyrimidoquinolines, a new series of the title compounds were synthesized and biologically screened for their antimicrobial and anti-oxidant activities. The intermediate compound, 2-amino-1-cyclohexyl-4-(3,4-dimethoxyphenyl)-1,4,5,6,7,8-hexahydroquinoline-3-carbonitrile (2), was prepared and allowed to react with oxalyl chloride to give the corresponding strategic starting material, 10-cyclohexyl-5-(3,4-dimethoxyphenyl)-4-oxo-3,4,5,6,7,8,9,10-octahydropyrimido[4,5-b]quinoline-2-carbonyl chloride 3. Compound 3 underwent diverse reactions with amines to give the corresponding carboxylic amides 4, with alcohols to give the carboxylic esters 5 and with hydrazine to give the carbohydrazide 8. Compound 8 reacted with aldoses to give the corresponding polyhydroxy(-)alkyl Schiff bases 9, which upon reaction with thioglycolic acid afforded the thiazolidinone-C-acyclic nucleosides 10. Several other pyrimidoquinolines incorporated to oxadiazole, iminothiazolidinones and thiadiazoles were synthesized starting from the 2-carbohydrazide derivative 8. Most of the newly prepared derivatives showed considerable antimicrobial activity against Gram +ve and Gram ?ve bacteria and anti-oxidant activity.     

Influence of the nature of the substituent in 3-(2-pyridyl)-1,2,4-triazole for complexation with Pd<Superscript>2+</Superscript>

The structure of four new palladium complexes [Pd(HL ² )Cl ₂ and Pd(L ^1–3 ) ₂ ] with 3-(2-pyridyl)-5-R-1,2,4-triazoles (R=H, CH₃, Ph respectively HL ¹ , HL ² , HL ³ ) was proposed based on IR, NMR, UV spectroscopy and MALDI mass spectrometry data analysis. It is found that the complexation of HL ² and HL ³ with Pd²⁺ ions results in a decrease of their fluorescence intensity and it is vice versa in case of HL ¹ . Furthermore, the influence of the substituent (R) in the 3-(2-pirydyl)-5-R-1,2,4-triazoles on the fluorescent and protolytic properties of HL ^1–3 was investigated.     

Four supramolecular transition metal(II) complexes based on triazole-benzoic acid derivatives: crystal structure,Hirshfeld surface analysis,and spectroscopic and thermal properties

Four new complexes [M(3-tba)₂(H₂O)₄] (1–3) and [Co(4-tba)₂(H₂O)₄] (4) {M = Zn (1), Ni (2), Co (3), 3-Htba = 3-(1H-1,2,4-triazol-1-yl)benzoic acid, 4-Htba = 4-(1H-1,2,4-triazol-1-yl)benzoic acid} have been synthesized under solvothermal conditions and structurally characterized by single crystal X-ray diffraction. Complexes 1–4 are also determined by elemental analysis, X-ray powder diffraction, IR and electronic spectroscopy. Single crystal X-ray diffraction reveals that complexes 1–3 are isostructural and they crystallize in the orthorhombic space group of Pbca, while complex 4 belongs to triclinic system with Pī space group. Based on different intermolecular hydrogen bonding and π···π stacking interactions, complexes 1–4 further assembled into 3D supramolecular frameworks. Hirshfeld surface analysis was used to further study the intermolecular interactions of the complexes. The thermogravimetric analyses (TGA) reveal that these complexes possess good thermal stability, and the differential scanning calorimetry (DSC) analyses show intense exothermic phenomena in the decomposition processes of triazole groups. Besides, the photoluminescence property of complex 1 in the solid state is also determined.     

Synthesis,structure, and catalytic activity of new aluminum and titanium complexes based on aminobisphenolate ligands containing bulky substituents

A reaction of aminobisphenols EtN{CH₂[(4-Alk)(6-But)(2-HO)C₆H₂]}₂, Alk = Me (1); Bu^t (2) containing alkyl substituents in the phenol groups with trimethylaluminum and tetra(tert-butoxy)titanium gave two new aluminum derivatives with the Me–Al bond: EtN{CH₂[(2-Alk)-(4-Bu^t)C₆H₂(2-O–)]}2Al–Me, Alk = Me (3); Bu^t (4), and two new titanium derivatives with the Bu^tO–Ti bond: EtN{CH₂[(2-Alk)(4-Bu^t)C₆H₂(2-O–)]}2Ti(O–Bu^t)₂, Alk = Me (5); But (6). The structures of new compounds were confirmed by NMR spectroscopy and elemental analysis. The structures of complexes 3 and 6 were studied by X-ray crystallography. Complexes 3 and 6 are monomeric in the solid phase: a coordination number of Al atom is 4, that of Ti atom is 5, in addition to the M–O bonds the M←N interactions are also present. Complexes 3–6 were studied as initiators of the ring-opening polymerization of ε-caprolactone. The resulting polymers are characterized by relatively high values of number average molecular weight, with the polydispersity being relatively low.     

Facile synthesis of some condensed 1,3-thiazines and thiazoles under conventional conditions: antitumor activity

1,3-Thiazine 3 was obtained from cinnamoyl thiourea derivative 2 as the kinetic control product. Refluxing of 2 with sodium ethoxide afforded pyrimidine derivative 4. Moreover, stirring of 2 with bromine/acetic acid gave thiazole 5 that was condensed with o-phenylene diamine forming benzimidazole 6. Heating of arylthiourea 8 with maleic anhydride or phenacyl chloride afforded thiazole derivatives 9 and 10, respectively. Condensation of compound 10 with o-phenylene diamine gave benzimidazole 11. Reaction of p-amino benzoic acid with chloro acetyl isothiocyanate, acetylacetone and ethylacetoacetate produced imidazole 14, enaminone 15 and crotonate 16 derivatives, respectively. Stirring a mixture of benzoyl isothiocyanate with 15 and/or 16 resulted in pyridine-2-thione 17. The yields of the prepared compounds were 41–93%. The experimental section is simple and easy. The detailed synthesis, spectroscopic data, IC₅₀ and antitumor activity of the synthesized compounds were reported. The cytotoxicity of the newly synthesized products showed that compound 4 is the most active compound towards the cancer cell line at which its reactivity is higher than that of the standard doxorubicin (anticancer reference drug).     

Synthesis and antiviral activities of novel penta-1,4-diene-3-one oxime derivatives bearing a pyridine moiety

A series of novel penta-1,4-diene-3-one oxime ether derivatives bearing a pyridine moiety were designed and synthesized, and their antiviral activities against tobacco mosaic virus (TMV) were evaluated. The results of the biological assay indicated that most of the title compounds exhibit good antiviral activities against TMV at 500 μg/mL. In particular, the title compounds 5c, 5j, 5o and 5p showed remarkable curative activities against TMV, with EC₅₀ values of 274.8, 299.2, 251.8 and 287.7 μg/mL, respectively, which were superior to that of ribavirin (379.8 μg/mL). This study indicates that penta-1,4-diene-3-one oxime ether derivatives bearing a pyridine moiety can serve as potential alternative templates in the search for novel, highly efficient, anti-plant viral agents.     

Supramolecular systems formed by calix[4]resorcinarenes and surfactants in chlorophorm

Capacity titration and ¹H NOESY 2D NMR were applied to investigation of intermolecular interactions and aggregation of amphiphilic calix[4]resorcinarenes (CRA 1, 2) modified with 1,2,4-triazine (1) and oxazine (2) functions in chloroform in the presence of cationic (3) and non-ionic (4) surfactants (SAA). Critical concentrations of micelle formation (CMC) indicate that the ability of CRA 1, 2 to form supramolecular aggregates like micelles or hybrid micelles with SAA 3, 4 only weakly depends on the constitution of CRA functional groups. In the case of the hybrid micelles, when CMC are defined by the nature of surfactants 3 or 4, the methyl and methylene groups of the hydrophobic fragments (CRA 1, 2) were found to interact with the hydroxy groups of SAA 3 and ethylene oxide moieties of SAA 4.     

Cyclization of pyrazolones: novel synthesis of pyrano,pyrido, pyrimido and spiropyrazole derivatives

Depending on the reaction conditions, two alternative cyclizations are possible for [3?+?3] cyclocondensation of pyrazolone derivative 1a and ethyl cyanoacetate of type pyrano [2,3-c] pyrazol-6(1H)-one 2 and pyrano [2,3-c] pyrazol-4(1H)-one 3. Keeping of enaminic system 3 and benzylidene malononitrile in the presence of catalytic amount of trimethylamine resulted in pyridine cyclization affording pyrazolopyranopyridine derivative 4, not 5. The pyrazolone derivative 6a was obtained as a result of the acid-mediated addition reaction between compound 1a, urea and/or ammonium thiocyanate. In addition, the bispyrazolone of type 6b was obtained from the condensation reaction of urea and pyrazolone derivative. The spiro compound 7 was obtained from the double-addition reaction of pyrazolone to cinnamoyl isothiocyanate. A one-pot three-component condensation of a 3-hydroxybenzaldehyde, pyrazolone 1a, urea and/or thiourea under Biginelli conditions resulted in tetrahydropyrazolo pyrimidine derivatives 8a and 8b, respectively. The acid-mediated reaction of benzaldehyde and pyrazolone derivative 1a in the presence of Ac₂O yielded styrylpyrazole derivative 9. The polyfunctionalized product 9 reacted with hydrazine to furnish pyrazolotriazoloe of type 10. Treatment of styrylpyrazole derivative 9 with aniline furnished the aniline derivative 11 and none of the expected polyheterocyclic derivative 12 was obtained. Compound 9 undergoes pyridine cyclization to produce 13 under the effect of urea. N-phenyl pyrazolone converted into pyrano-dipyrazolone derivative 14. Pyran of type 14 underwent a ring transformation upon treatment with urea and/or thiourea to give the same dipyrazolo pyrimidine derivative 15. The newly synthesized compounds were characterized by FT-IR, ¹H-NMR, ¹³C-NMR, ESI/LC-MS and elemental analysis.     

Structural studies of nickel(II) complexes with 1-<Emphasis Type="Italic">tert</Emphasis>-butylimidazole-2-thione and 3-phenyl-5-methyl-pyrazole ligands

The nickel(II) complexes dichlorobis(1-tert-butylimidazole-2-thione)nickel(II) [Ni(tm ^t-Bu)₂Cl₂] (1), dinitratobis(1-tert-butylimidazole-2-thione)nickel(II) [Ni(tm ^t-Bu)₂(NO₃)₂] (2), dichloro-bis(3-phenyl-5-methyl-pyrazole)(1-tert-butylimidazole-2-thione)nickel(II) [Ni(pz^Ph,MeH)₂(tm ^t-Bu)Cl₂] (3) and dinitratobis(3-phenyl-5-methyl-pyrazole)(1-tert-butylimidazole-2-thione)nickel(II) [Ni(pz^Ph,MeH)₂(tm ^t-Bu)(NO₃)₂] (4) have been synthesized and studied. The single crystal X-ray diffraction analysis was carried out for 1 and 4 {Bruker Kappa Apex-II CCD diffractometer, MoK _α radiation}. Crystal data for 1: monoclinic C2/c, a = 16.949(2) Å, b = 8.6647(10) Å, c = 15.461(3) Å, β = 117.662(4)°, V = 2011.1(5) ų, Z = 4, D _calc = 1.460 g/cm³. Crystal data for 4: triclinic P-1, a = 9.9775(7) Å, b = 11.2254(8) Å, c = 14.8068(10) Å, α = 75.401(4)°, β = 87.422(4)°, γ = 74.874(4)°, V = 1548.86(19) ų, Z = 2, D _calc = 1.405 g/cm³. Coordination core of complex 1 adopts distorted tetrahedral geometry whereas core 4 has distorted octahedral geometry. The bonded nitrates are of two types coordinating as monodentate and bidentate ligands.     

Synthesis,antibacterial, and antiviral activities of novel penta-1,4-dien-3-one derivatives containing a benzotriazin-4(3<Emphasis Type="Italic">H</Emphasis>)-one moiety

A series of penta-1,4-dien-3-one containing a benzotriazin-4(3H)-one moiety were prepared and evaluated for their antibacterial and antiviral activities. Bioassays indicated that some compounds exhibited good antibacterial and antiviral activities. Among them, the EC₅₀ values of compound 6d against Xanthomonas axonopodis pv. citri and compound 6l against Ralstonia solanacearum were, respectively, 22.45 and 34.77 μg/mL, which were better than that of thiodiazole copper (51.35 and 87.26 μg/mL, respectively). Meanwhile, some title compounds were found to show remarkable antiviral activities against tobacco mosaic virus (TMV). These results indicated that penta-1,4-dien-3-one derivatives containing benzotriazin-4(3H)-one moiety could play significant roles in searching for novel agrochemicals.     

Biomimetic oxidation of catechol employing complexes formed in situ with heterocyclic ligands and different copper(II) salts

In the present work, catecholase activity is presented. The complexes were prepared by condensation of the organic ligand pyrazolyl L ₁ –L ₄ and copper(II) ion in situ. The pyrazolyl compounds L ₁ –L ₄ used in this study are: L ₁ is (3,5-dimethyl-pyrazol-1-ylmethyl)-(4-methyl-pyridin-2-yl)-pyrazol-1-ylmethyl-amine; L ₂ is 1-{4-[(3,5-dimethyl-pyrazol-1-ylmethyl)-pyrazol-1-ylmethyl-amino]-phenyl}-ethanone; L ₃ is 1-{4-[(3,5-dimethyl-pyrazol-1-ylmethyl)-[1,2,4]triazol-1-ylmethyl-amino]-phenyl}-ethanone, and L ₄ is 2-[(3,5-dimethyl-pyrazol-1-ylmethyl)-[1,2,4]triazol-1-ylmethyl-amino]-6-methyl-pyrimidin-4-ol, and copper ions salts Cu(II) are (Cu(CH₃COO)₂, CuCl₂, Cu(NO₃)₂ and CuSO₄). In order to determine factors influencing the catecholase activity of these complexes, the effect of ligand nature, ligand concentration, nature of solvent and nature of counter anion has been studied. The best activity of catechol oxidation is given by the combination formed by one equivalent of ligand L ₂ and one equivalent of Cu(CH₃COO)₂ in methanol solvent which is equal to 9.09 µmol L^?1 min^?1. The Michaelis–Menten model is applied for the best combination, to obtain the kinetic parameters, and we proposed the mechanism for oxidation reaction of catecholase.