A Reusable Efficient Green Catalyst of 2D Cu-MOF for the Click and Knoevenagel Reaction

[Cu(CPA)(BDC)]n (CPA = 4-(Chloro-phenyl)-pyridin-4-ylmethylene-amine; BDC = 1,4-benzenedicarboxylate) has been synthesized and structurally characterized by single crystal X-Ray diffraction measurement. The structural studies establish the copper (II) containing 2D sheet with (4,4) square grid structure. The square grid lengths are 10.775 and 10.769 Å. Thermal stability is assessed by TGA, and subsequent PXRD data establish the crystallinity. The surface morphology is evaluated by FE-SEM. The N2 adsorption−desorption analysis demonstrates the mesoporous feature (∼6.95 nm) of the Cu-MOF. This porous grid serves as heterogeneous green catalyst with superficial recyclability and thermal stability and facilitates organic transformations efficiently such as, Click and Knoevenagel reactions in the aqueous methanolic medium.

1-ALKYL-3-METHYL-4-HYDROXYIMINO-2-PYRAZOLINE-5-ONES AS EXTRACTION REAGENTS

With nitrosation of the corresponding 1-R-3-methylpyrazole-5-one (R = C4H9, C5H11, C6H13, C7H15, C8H17, C6H5) in acidic aqueous methanolic medium at 0-5 °C a series of 1-alkyl-3-methyl-4-hydroxyimino-2-pyrazolin-5-ones with a yield of 72-85% were synthesized. The compounds are soluble in CHCl3, C2H4Cl2, C6H5CH3, i-C4H9OH, CCl4, C2H5OH, slightly soluble in C6H14, H2O. They can be recrystallized from a mixture of C6H14: C6H5CH3 = 5: 1 or isooctane. The structure of the compounds was confirmed by the data of ECR, IR, Raman spectroscopy and TLC data. The interphase distribution of oxyiminopyrazolones between chloroform and aqueous solutions was studied as a function of pH. In alkaline media, the reagents completely transferred into the aqueous phase. In acidic solutions, up to 1 mol/l HCl, the compounds are in the organic phase. The maximum values of the partition coefficient are observed for the reagents with the maximum length of the aliphatic radical. The effect of the length of aliphatic radical at the first position of the pyrazoline ring on their extraction properties were studied by example of extraction of nickel and copper (II) ions. The length of the radical does not affect the composition of the recoverable complexes of nickel and copper (II). In all cases the ratio is close to 1:2. Extraction proceeds through a cation-exchange mechanism. Replacement of the phenyl radical in the first position of the pyrazoline ring by an aliphatic resulted to the increase in partition constants of the reagents between chloroform and aqueous solutions. The range of pH values of the maximum extraction of elements was widened. The capacity of the extractant for metals also increased. At the same time, the pH50 extraction values remained practically unchanged. In the case of 0.05 mol/l solution of 1-phenyl-3-methyl-4-oxyimino-2-pyrazolin-5-one in chloroform, when the extract was saturated with the metal ion, precipitation of the complex was observed.For citation:Lesnov A.E., Pavlov P.T., Pustovik L.V., Sarana I.A. 1-Alkyl-3-methyl-4-hydroxyimino-2-pyrazoline-5-ones as extraction reagents. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 5. P. 30-36.

Electrochemical Oxidation of Ethinylestradiol on a Commercial Ti/Ru0.3 Ti0.7O2 DSA Electrode

The electrochemical oxidation of the hormone ethinylestradiol in an aqueous-methanolic medium by the application of a constant current of 40 mA cm−2 in a flow cell with a commercial Ti/Ru0.3 Ti0.7O2 electrode was evaluated. The effect caused by the use of NaCl as a support electrolyte was also investigated. Hence, HPLC-UV analyses revealed that ethinylestradiol was almost totally consumed after a 60 min reaction time in the presence of NaCl. Conversely, much lower degradation rates were obtained when NaCl was not employed. Moreover, direct infusion ESI-MS and GC-MS analysis revealed that apparently no degradation products had been formed under these conditions. Hence, this study clearly demonstrated that such electrochemical treatment can be efficiently used to promote the complete degradation (and probably mineralization) of the hormone ethinylestradiol.

SYNTHESIS AND CHARACTERIZATION OF MALONIC ACID DIHYDRAZIDE AND ITS METAL COMPLEXES

A new series of complexes was synthesized by the reaction between malonyl dihydrazide (MAH) and manganese, copper, nickel, zinc, cadmium, cobalt and ferric salts in methanolic medium. The complexes were characterized by elemental analysis, molar conductance measurements, electronic, IR and 1H NMR spectral studies. Based on the results obtained, the stoichiometry of Fe(III)-MAH and Co(III)-MAH was proposed to be 1:3 and that for Cu(II)-MAH, Cd(II)-MAH, Zn(II)-MAH, Mn(II)-MAH, Ni(II)-MAH was proposed to be 1:2 (M:L). It was suggested that the nitrogen present in the azomethine (>C=N-) group of the enolic form present in the ligand was involved in the formation of complexes. A clear picturisation indicating the bonding sites were depicted for each complex. The metal complexes exhibit different geometries such as tetrahedral, square planar and octahedral arrangements.

Inhibition of β-Lactamase II of Bacillus cereus by Penamaldic Derivatives of Penicillins

ABSTRACT The penamaldic derivatives of amoxicillin, ampicillin, and penicillins G and V, stabilized with Zn2+, were obtained from a methanolic medium. The enzymatic kinetic results show that the these derivatives elicit reversible inhibition of the enzyme metallo-β-lactamase from Bacillus cereus, with inhibition constant values determined at pH 7.0 and 25°C.