Study of the electron interactions of polysubstituted azoles by PMR and IR spectroscopy

The IR and PMR spectra of an extensive series of methyl derivatives of aromatic and heteroaromatic compounds were investigated. With a few exceptions, the experimental data on the chemical shifts of the protons and the intensity of the band of the symmetrical stretching vibration [(A_CH)^1/2] for five- and six-membered heterorings can be united in a single reaction series with polysubstituted toluenes within the framework of an additive scheme. The (A_CH)^1/2 values correlate satisfactorily with the calculated (by the CNDO/2 method) total charges on the carbon and hydrogen atoms of the methyl group. In contrast to the intensities of the IR bands, linear relationships between the chemical shifts and the charges on the hydrogen atoms are observed only within the limits of particular reaction series. The lack of a unified relationship was interpreted as being the result of the effect of the ring current, the contribution of which to the value depends on the nature of the heteroatom.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1110–1119, August, 1977.     

Intramolecular cyclization of 4-amino-3-alkylsulfanyl-1,2,4-triazoles as a method for annelation of thiadiazine and thiadiazole rings

4-Amino-5-(pyridin-4-yl)-4H-1,2,4-triazole-3-thiols reacted with N-substituted isatins to give 2-oxo-3-[5-(pyridin-4-yl)-3-sulfanyl-4H-1,2,4-triazole-4-ylimino]-2,3-dihydro-1H-indoles which were treated with phenacyl bromides to obtain the corresponding S-phenacyl derivatives. The latter underwent base-catalyzed intramolecular cyclization with formation of 6,7-dihydro-5H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazines spiro-fused to 2-oxo-2,3-dihydro-1H-indole fragment at C³. Analogous cyclization of 2,6-di-tert-butyl-4-[5-hetaryl-3-(2-aryl-2-oxoethylsulfanyl)-4H-1,2,4-triazole-4-ylimino]cyclohexa-2,5-dienones involved the imino nitrogen atom to produce the corresponding 6-aroyl-5-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-hetaryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles.     

On some peculiarities of phthalimide formation in the oxidative ammonolysis of o-xylene

In the oxidative ammonolysis of o-xylene on oxide catalysts, phthalimide can be obtained from phthalodinitrile through an intermediate phthalocyanine step. The catalyst ability to form phthalocyanine can be used to estimate its selectivity to phthalimide.

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Chemical and electrochemical synthesis,structure, photoluminescent properties,and biological activity of 4-methyl-N-[2-[(Z)-2-(2-pyridyl)alkyliminomethyl]phenyl]benzenesulfamide zinc(II) complexes

A series of Zn(II) complexes of the tridentate azomethine ligands, condensation products of 2-(N-tosylamino)benzaldehyde and 2-aminoalkylpyridines, were synthesized by chemical and electrochemical methods. All compounds were characterized on the basis of C, H, N elemental analysis, Fourier-transform infrared, ¹H nuclear magnetic resonance, UV–Vis, and photoluminescence studies. The local atomic structures of complexes were determined from analysis of extended X-ray absorption fine structure and X-ray absorption near-edge structure of Zn K-edges. The molecular structure of chloro-{4-methyl-N-[2-[(Z)-2-pyridyl)ethyliminomethyl]phenyl]benzenesulfamide}zinc(II) was determined by X-ray single-crystal diffraction. The fluorescence spectra show that these complexes in dimethyl sulfoxide solutions at room temperature emit bright blue luminescence at 435–461 nm with fluorescence quantum yields in the range of 0.20–0.31. The assignment and the nature of the bands in experimental UV–Vis spectra of complexes were analyzed using time-dependent density functional theory calculations B3LYP/6-31G(d). The azomethines and complexes of zinc have been screened for their antibacterial, protistocidal, and fungistatic activities against Penicillium italicum, Colpoda steinii, Escherichia coli 078, and Staphylococcus aureus P-209, and the results are compared with the activity of furazolidone, chloroquine, and Fundazol.     

Synthesis and structural studies of 5,7(4,6)-di(<Emphasis Type="Italic">tert</Emphasis>-butyl)-2-(6,8-dimethyl-4-chloroquinolin-2-yl)-1,3-tropolones by quantum-chemical methods and two-dimensional correlation NMR spectroscopy

4,6-Di(tert-butyl)-2-(quinolin-2-yl)-1,3-tropolone (7′) was isolated for the first time from the acid-catalyzed reaction of 2-methyl-substituted nitrogen heterocycles with 1,2-benzoquinones, which proceeds with the expansion of the o-quinone ring to give mainly isomeric 5,7-di(tert-butyl)-2-(quinolin-2-yl)-1,3-tropolone.     

Intramolecular cyclization of S-alkyl derivatives of aminomercaptoimidazoles and -benzimidazoles as a method for the annulation of the thiadiazine ring

A method was developed for the annulation of the tetrahydrothiadiazine moiety to the imidazole and benzimidazole rings through intramolecular cyclization of S-alkyl derivatives of aminomercaptoimidazoles and -benzimidazoles. The factors controlling the stereoselectivity of the formation of the tetrahydrothiadiazine ring were revealed.     

Synthesis,physicochemical and coordination properties of 5,15-diphenyltetramethyltetraethylporphyn nitro derivatives

The 5,15-diphenyl-3,7,13,17-tetramethyl-2,8,12,18-tetraethylporphyrin nitro derivatives containing the nitro groups in the meso-positions of the porphyn ring and/or para-positions of phenyl rings were synthesized. Porphyrins were characterized by electron absorption, ¹H NMR, and IR spectra. The purity and individuality of the synthesized compounds was proved by TLC and elemental analysis. Kinetic parameters of complexation reactions of the synthesized porphyrins with copper acetate in pyridine and in the mixed solvent benzene-acetic acid (7:3) depend on the degree of deformation of the tetrapyrrole cycle, on the solvation effects and electronic effects of the nitro groups.     

Synthesis of benzo[<Emphasis Type="Italic">g</Emphasis>]quinoline-5,10-diones

Addition of HCl to 2-amino-3-(4-methyl-3-oxopentynyl)-1,4-naphthoquinone in CHCl₃ at 20 °C is followed by its cyclization to 4-chloro-2-isopropylbenzo[g]quinoline-5,10-dione. Chlorine atom in this compound can be easily replaced by dialkylamino group upon treatment with secondary amines. 4-Dialkylamino-2-isopropylbenzo[g]quinoline-5,10-dione is also formed by the direct reaction of the starting ketone with secondary amines. Syntheses of 2-amino-3-(4-methyl-3-oxopentynyl)-1,4-naphthoquinone from 2-bromo-and 2-amino-3-iodo-1,4-naphthoquinones are also described. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2381–2385, December, 2007.