Thiacrown compounds: Synthesis and properties. (Review)

Data of the last 15 years on the synthesis and properties of various thiacrown compounds containing 2–8 sulfur atoms in the ring are reviewed.M. V. Lomonosov Moscow State University, Moscow, RussiaTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1587–1618, December, 1999.     

15N NMR spectral parameters of compounds of the N-methylpyrazole series

The¹⁵N NMR chemical shifts and¹⁵N-¹H SSCCs are presented for substituted N-methylpyrazoles with substituents such as CH₃, NO₂, Br, Cl, NH₂, O=CNH₂, O=CPh, and COOH at the carbon atoms. The¹⁵N chemical shifts of the cyclic atoms of nitrogen and the nitro groups are discussed as well as the geminal and vicinal SSCCs of the ring nitrogen atoms with the hydrogen atoms of the CH and CH₃ fragments.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117334 Moscow. D. I. Mendeleev Chemico-Technological Institute, Moscow, Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2554–2561, November, 1992.     

New approach to the synthesis of dibenzodithia-and benzothiaazacrown ethers via the aromatization of 2-alkylthio(arylthio)cyclohexanes during bromination

A new scheme for the synthesis of dibenzodithiacrown ethers is proposed based on the use of substituted phenol derivatives as intermediates, prepared by aromatization of 2-alkylthio(arylthio)cyclohexanes during bromination. 1,7-Dithia-8,9,17,18-dibenzo-18-crown-6 and 1,10-dithia-11,12,20,21-dibenzo-21-crow-7 without isomers relative to position of the sulfur atoms have been synthesized, and also new thiadiazamacroheterocycles — 1,4,7-trioxa-10,19-dithia-13,16-diaza-12,17-dioxo-8,9,14,15,20,21-tribenzoheneicosane and 1,4,7,10-tetraoxa-13,22-dithia-16,19-diaza-15,20-dioxo-11,12,17,18,23,24-tribenzotetracosane.M. V. Lomonosov Moscow State University, Moscow 119899. M. V. Lomonosov Moscow State Academy for Fine Chemical Technology, Moscow 117571. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 121–127, January, 1997.     

Phenolic lipid from Azotobacter chroococcum

Summary From the total cell lipids of the nitrogen-fixing bacteriumAzotobacter chroococcum 92 a previously unknown lipid has been isolated which has been identified as a 1-alkyl-3,5-dihydroxybenzene. The alkyl chains of the main components of the lipid fraction have a normal structure and contain 19 and 21 carbon atoms.M. M. Shemyakin Institute of Bioorganic Chemistry, USSR, Moscow, All-Union Scientific-Research Institute of Microbiological Agents for Plant Protection and Bacterial Preparations, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 494–499, July–August, 1977.     

Di- and triphenylphosphonites of 2,2-di-(p-hydroxyphenyl)propane

Starting from 2,2-di-(p-hydroxyphenyl)propane and phenylphosphonic acid tetraethylamide we have prepared the first oligoarylenephosphonites with spatially separated phosphorus functionalities. We have studied the principal chemical properties of these compounds. We have shown the capacity of oligoarylenediphosphonites to coordinate with transition metals through one or all phosphorus atoms with formation of mono- and oligo complexes. We have found that monocomplexes can undergo degenerated metallotropic rearrangements.V. I. Lenin Moscow Pedagogical State University, 119883 Moscow, Russia. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 12, pp. 2777–2784, December, 1992.     

Crystal-chemical mechanism in the fundamental absorption of MgO crystal

Correlations between structural, thermal, and optical properties of MgO are shown as linear dependences of the energy ε of the photons absorbed by the crystal on the enthalpy of sublimation ΔH of the crystal to molecules, atoms, ions, and electrons. This dependence holds true only if in different schemes of crystal sublimation the values of ΔH are calculated for the cell MgO rather than its formula unit. M. V. Lomonosov Moscow State University, Geological Faculty. IGEM, Moscow. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 2, pp. 283–288, March–April, 1996. Translated by I. Izvekova     

Reactions of polyhalogenopyridines. 14. Reaction of isomeric dichlorocyanopyridines and pentachloropyridine with potassium ethylxanthate

The reactions of isomeric tetrachlorocyanopyridines with potassium ethylxanthate were studied. It was found that tetrachloro-2-cyanopyridine was converted successively into 4-mono- and then 3,4-bisethylxanthate derivatives. In the presence of potassium ethylxanthate the last derivative undergoes intramolecular cyclization with the formation of derivatives of 1,3-dithiolo[4,5-c]pyridine. In the case of other initial polychloropyridines processes involving substitution of the chlorine atoms by the ethylxanthate fragment, sometimes accompanied by the loss of COS molecules, were observed instead of heterocyclization. For Communication 13, see [1]. Chernogolovka Institute of Chemical Physics, Russian Academy of Sciences, Chernogolovka 142432. M. V. Lomonosov Moscow State University, Moscow 119899. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1510–1520, November, 1997.     

Stereoselective synthesis and structure of 3,4-trans-6-amino-4-aryl-3-carbamoyl-5-cyano-1,2,3,4-tetrahydropyridin-2(1H)-thiones

Condensation of thiocarbamoylacetamide with arylidenemalononitrile or the three-component condensation of thiocarbamoylacetamide with aldehydes and malononitrile in the presence of triethylamine occurred regioselectively to give triethylammonium-6-amino-4-aryl-3-carbamoyl-5-cyano-1,4-dihydropyridine-2-thiolates. Protonation of the latter occurred stereoselectively to give 3,4-trans-6-aryl-3-carbamoyl-5-cyano-1,2,3,4-tetrahydropyridin-2(1H)-thiones. The¹H NMR spectrum and single x-ray crystallography indicate that the dihydropyridine ring has he sofa conformation with trans-pseudodiaxial orientation of the Ar and CONH₂ groups and trans-pseudoequatorial orientation of atoms 3-H and 4-H.N. D. Zelinskii Organic Chemistry Institute, Russian Academy of Sciences, Moscow, 117913. A. N. Nesmeyanov Institute of Elementoorganic Chemistry, Russian Academy of Sciences, Moscow, 117813. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1376–1382, Octoberm 1996. Original article submitted June 10, 1996.     

Isomerization of dichloro- and difluorobenzenes: A quantum-chemical consideration

The AM-1 method with full optimization of geometry was used to study several proposed isomerization mechanisms for dichloro- and difluorobenzenes on active centers as proton donors. Preferred positions of proton addition in dihalobenzenes were studied and protonation and activation energies for intramolecular migration of hydrogen and halogen atoms were determined. It was shown that the isomerization mechanisms are the same for dichloro-and difluorobenzenes and result from a 1,2-shift of the halogen. The activation energy for migration of a fluorine atom in difluorobenzenonium cations is substantially higher than for a chlorine atom in dichlorobenzenonium cations. The data obtained on the mechanism have experimental verification.A. N. Nesmeyanov Institute Heteroorganic Compounds, Russian Academy of Sciences, 117813 Moscow. N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117433 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 731–737, March, 1992.     

Ionization constants of a number of alkaloids used in medicine

The pK_a values of a number of alkaloids in water or in aqueous ethanol have been measured by the potentiometric titration method: nuphleine — 4.59, 6.98; brevicolline — 5.17, 8.02; chelidonine — 6.40; sanguinarine — 7.32; chelerythrine — 7.53; stepharine — 8.48; d-pseudoephedrine — 9.49. For nuphleine and brevicolline, each of which has two nitrogen atoms capable of protonation, assignments have been made of pK_a values to the corresponding atoms on the basis of the results of UV spectroscopy.All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 337–341, May–June, 1984.     

Substitutive sulfotrioxidation of branched perfluoroolefins

We have studied the insertion of SO₃ into the C-F bond of perfluoroolefins under conditions of electrophilic catalysis. It was shown that sufficiently high allylic mobility of the fluorine atoms is only preserved when in the allylic triad, in addition to the substituted fluorine; also not less than three fluorine atoms are present in the and positions.A. N. Nesmeyanov Institute of Organoelemental Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 10, pp. 2341–2346, October, 1992.     

Supported complexes of cupric chloride with DMF as catalysts in the reaction of CCl4 withn-decane

The complex of cupric chloride with DMF immobilized on the surface of silica gel exhibits high catalytic activity in the reaction of tetrachloromethane withn-decane. The fact that the reaction is inhibited by phenols and oxygen implies that it occurs by a radical mechanism. The immobilized catalyst that contains copper atoms connected through chlorine bridges and organic donor ligands is the most effective. Presented at the First Moscow Workshop on Highly Organized Catalytic Systems. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1835–1838, October, 1997.     

Structural features of the copper(II) chloride-triphenylphosphine-N-(2-pyrimidyl)imine complex in crystal and solution

The structure of the copper(II) chloride-triphenylphosphine-N-(2-pyrimidyl)imine complex in crystal and solution was investigated by x-ray analysis and EPR. It was found that despite the difference in the structures of the dissolved and crystalline complexes, the exocyclic nitrogen atom is contained in the coordination sphere of the metal together with the nitrogen atom of the heterocycle in both cases due to the electronic effect of the phosphorus atom. In the crystal, the copper atom is coordinated with two chlorine atoms and two molecules of the ligand, and the distance from the copper cation to the nitrogen atoms of the pyrimidine rings is significantly less than the distance to the nitrogen atoms of the phosphinimine groups (2.0 and 2.8 Å, respectively). The coordination polyhedron formed as a result is a strongly distorted axially asymmetric octahedron. In dissolution, the chlorine anions are substituted by molecules of the solvent, the complex acquires axial symmetry, and four nitrogen atoms from two ligands form a planar square with a copper(II) cation in the center.A. N. Nesmeyanov Institute of Organoelemental Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 118–125, January, 1992.     

Structure of lehmannine N-oxide

The molecular and crystal structure of lehmannine in its monohydrate has been studied by x-ray structural analysis. Rings A, B, and C have the chair form and ring D the half-chair form in which the deviations of the atoms from their mean-square plane does not exceed 0.06 Å.Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Institute of Crystallography, Academy of Sciences of the USSR, Moscow. V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 757–763, November–December, 1981.     

Synthesis of mono- and disubstituted tetra(tert-butyl)porphyrazines

Bromination of tetra(tert-butyl)porphyrazine by N-bromosuccinimide in chloroform results in the formation of mono- and dibromides, substitution for the bromine atoms of which produced the corresponding cyano, phenoxy, phenylthio, styryl, phenylethynyl and piperidino derivatives. From the monobromide and 2,2-bis(p-hydroxyphenyl)propane, the dimeric porphyrazine 2,2-bis[p-tetra(tert-butyl)porphyrazyloxyphenyl]propane was similarly obtained.Scientific Research Institute of Organic Intermediate Products and Dyes, Moscow 103787. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1206–1212, September, 1994. Original article submitted September 6, 1994.     

Gas phase electron diffraction study of the hafnium perchlorate molecule

The structure of the Hf(ClO₄)₄ molecule was investigated by electron diffractometry in the gas phase. The model with D₄ symmetry is in best agreement with experimental data; it contains ClO₄ fragments in the form of distorted tetrahedra bridged by two oxygen atoms to the central Hf atom. Ivanovo Chemical Technological Academy. Moscow State University, Chemical Faculty. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 3, pp. 487–493, May-June, 1996.     

Reactivity and electronic structure of the ground and excited states of oxazole, 2-phenyloxazole, and 2-phenylthiazole

The relationship of the electronic structure, of oxazole, 2-phenyloxazole, and 2-phenylthiazole to the properties of the electronic excited states and transitions is examined. Spectral properties of these compounds in the free state (no effect from external perturbations) and in complexes with the proton and aprotic acids are measured and calculated by quantum-chemical PPP/S (-approximation), and INDO/S (sp-basis) methods. Features of the electronic excitation of the atoms and the vibronic interaction of bonds in the singlet and triplet states are examined for a change of the various structural forms of azoles, which determine their spectral fluorescence properties and reactivity. Possible direction control of reactions and optimized syntheses of new compounds with given properties are discussed based on a study of the properties of the ground and excited states.Russian People's Friendship University, Moscow 117302 N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913 Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 948–974, July, 1999.     

Synthesis of the N-terminal tripeptide sequence of oxytocin with various protective groups for the cysteine residue

The influence of the nature of the protective groups at the sulfur and nitrogen atoms in the cysteine molecule on the reactivity of this amino acid in the peptide condensation reaction has been investigated. The synthesis of the N-terminal tripeptide sequence of oxytocin was selected as a model reaction. For identifying the compounds synthesized and checking their purity, in addition to traditional physicochemical methods (TLC, melting points, angles of optical rotation), wide use has been made of the¹³C NMR method.All-Union Scientific-Research Institute of the Technology of Blood Substitutes and Hormone Preparations, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 684–692, September–October, 1989.     

Crystal and molecular structure of 1:1 molecular complexes of triphenyl-N-(4-methylpyridyl-2)phosphinimine and triphenyl-N-(3-methylpyridyl-2)phosphinimine with perchloric acid

X-ray diffraction analysis has been used to determine the crystal structures of the 1:1-composition products of protonation by perchloric acid of isomeric triphenyl-N-(4-methylpyridyl-2)phosphinimine (1) and triphenyl-N-(3-methylpyridyl-2)phosphinimine (2). The structures were refined toR=0.048 andR=0.052, respectively, using 2274 (1) and 2647 (2) reflections. The protonation centers are located at the sites of N atoms of the pyridine ring (1) and the phosphinimino group (2). The distribution of the bond lengths in the cations suggests that a significant contribution is made by a phosphonic structure with positive charges localized on the P atoms. N-H...O hydrogen bonds, with lengths of 2.890(4) and 3.020(3) Å, connect cations and anions in both structures.A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 629–635, March, 1992.     

Complex formation of 1,4,7-tris(β-diphenylphosphinylethyl)-1,4,7-triazacyclononane with divalent copper salts

An investigation of the monoligand complex of 1,4,7-tris(-diphenylphosphinylethyl)-1,4,7-triazacyclononane with divalent copper has been carried out in various solvents using electronic, IR, and ESR spectroscopy. It was found that the five-coordination polyhedron formed in the complex involves only donor atoms of the ligand and has the structure of a tetragonally elongated square pyramid with two nitrogen atoms and two oxygen atoms at the base and a nitrogen atom at the apex. Compared with the copper(II) complex with the corresponding acid, 1,4,7-tris(-dihydroxyphosphinylethyl)-1,4,7-triazacyclononane, the coordination compound studied has a higher order of symmetry. The absence of observable distortions in the case of the acid is probably connected with steric interaction of the bulky phenyl substituents in the test ligand.A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, Moscow 117813. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 594–601, March, 1992.