Synthesis of (α-nitroalkyl-ONN-azoxy)furoxan derivatives

The first synthesis of 4-(α-nitroalkyl-ONN-azoxy)-3-methylfuroxans was accomplished by the reaction of 4-amino-3-methylfuroxans with pseudo nitrols in the presence of dibromoisocyanurate.     

The stereoselective synthesis of γ-lactam derivatives through N(1)-C(4) one carbon ring expansion of β-lactam derivatives

The base induced ring opening of β-lactam derivatives, 3, 5, 7, 9, 11 with LDA gave γ-lactam derivatives, 4, 6, 8, 10, 12 stereoselectively. The γ-lactam derivatives were formed stereoselectively depending on C-3 substituent of β-lactam derivatives.     

Reaction of amino acid derivatives with C_(60)

Ammo acid derivatives react with C60 at 110-120℃to form adduct compounds.The products were isolated by column chromatography and were identified by FD-MS,UV-Vis,FT-IR and 13C NMR spectroscopies.     

Synthesis of 1-(1-aryl-1H-1,2,3-triazol-4-yl)-β-carboline derivatives

Reaction of 5-methyl-1-aryl-1H-1,2,3-triazole-4-carbocylic acid chlorides with tryptamine derivatives afforded substituted 1-aryl-N-[2-(1H-indol-3-yl)ethyl]-5-methyl-1H-1,2,3-triazole-4-carboxamides. At heating these compounds in toluene in the presence of POCl₃ and P₂O₅ Bischler-Napieralski cyclization occurs giving 1-(1-aryl-5-methyl-1H-1,2,3-triazol-4-yl)-4,9-dihydro-3H-β-carbolines that can be transformed into β-carboline and tetrahydro-β-carboline derivatives.     

Preparation and properties of derivatives of dithiolylidene-(4′-phenyldiazonium)acetonitrile

Thefluoroborates of (4,5-dimethyl-1,3-dithiolylidene)-(4-phenyldiazonium)acetonitrile and (4,5-ethylenedithio-1,3-dithiolylidene)-(4-phenyldiazonium)acetonitrile have been prepared; these compounds are photosensitive in the visible region of the spectrum. The quantum yield in the photolysis of the fluoroborates in acetonitrile solution amounts to 0.1 moteleinstein.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, p. 179–181, February, 1994. Original article submitted November 29, 1993.     

Direct synthesis of per(poly)fluoroalkylmethyl-substituted electrophilic cyclopropane derivatives

A convenient and direct per(poly)fluoroalkylmethyl-mtroducing cyclopropanation reaction was described. In the presence of CrCl3/Fe, per(poly)fluoroalkyl iodides reacted with diethyl allylmalonate and its analogs to give per(poly)fluoroalkylmethyl-substituted electrophilic cyclopropane derivatives in high yields. This reaction was considered to proceed by two steps: radical addition followed by cyclopropanation.     

Synthesis of 4,4′-(arylmethylene)bis(3-methyl-1H-pyrazol-5-ol) derivatives in water

An environmentally friendly and simple method for the synthesis of some 4,4′-(arylmethylene)bis(3-methyl-1H-pyrazol-5-ol) derivatives via a one-pot pseudo five-component reaction of hydrazine hydrate, ethyl acetoacetate and aldehydes in water using pyridine trifluoroacetate or acetic acid at 70 °C is reported.     

Reactions of N-(Β-aminoethyl)piperazine and its derivatives

The alkylation, cyanoethylation, and heterocyclization reactoins of N-(-amonoethyl)piperazine and its derivatives, dicarboxylic acid imides, have been investigated. A new method has been proposed for the synthesis of 1,4-diazobicyclo[2.2.2]octane via pyrolytic cleavage of N,N-bis[piperazinoethyl]ethylenediamine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 381–385, March, 1991.     

Optical resolution of (±)-N-acylnorfenfluramine derivatives by preferential crystallization

Three stable and one unstable conglomerates (i. e. eutectic mixtures of D and L crystals) were found among nine synthesized (±)-N-acylnorfenfluramine derivatives. Optical resolution of the stable conglomerates could be achieved by preferential crystallization method only under nonisothermal conditions.     

Photochromism of cis(z)-1,2-bispyrryl-substituted ethene derivatives

Photochromism of two bispyrryl-substituted ethenes, 2, 3-bis-(1-p-methoxyphenyl-5-phenyl-2-methyl-3-pyrryl)-2-butene (BPE1) and 2,3-bis(1-p-bromophenyl-4-phenyl-2-methyl-3-pyrryl)-2-butene (BPE2), was studied by laser flash photolysis technique. The results indicate that photocyclization of these compounds proceeds mainly via the excited triplet state, and the cis-trans isomerization proceeds mainly via the excited singlet state. After UV laser pulse irradiation, both photocylization and cis-trans isomerization of BPEl occur, but photocydization is the main reaction. On the other hand, laser photolysis of BPE2 leads mainly to photocydization. The effects of the substituents on the photochromic mechanism are also discussed.     

Quantum chemical studies on antimalarial of artemisinin (qinghaosu) derivatives

In this paper theoretical studies were performed on artemisinin (qinghaosu) derivatives with semiempirical quantum chemical methods AMI and PM3. The antimalarial activity -logC has an obvious correlation with the net charge of C(16) and bond orders of bonds O(1)-C(10), O(2)-C(6), O(1)-O(2) and O(5)-C(16). According to the calculation results, we derived structure-activity relationship, presented the probable pharmacophore of qinghaosu derivatives and the interaction fashion between the drugs and the plasmodium receptor.     

Fragmentation of (η5-cyclopropentadienyl)iron carbonyl derivatives of carboranes(12) under electron impact

Mass spectra of (⁵-cyclopentadienyl)iron dicarbonyl derivatives of carborane(12), CpFe(CO)₂C₂H₁₁B₁₀ and CpFe(CO)₂COC₂H₁₁B₁₀, were studied. The effect of the carboranyl radical and the fragmentation of the organometallic moiety (decarbonylation and rearrangement with migration of the Cp ring to the carboranyl radical) and that of the organometallic moiety on the dehydrogenation of carborane were observed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 484–486, March, 1995.This work was supported by the Russian Foundation for Basic Research, project no. 94-03-08126.     

First synthesis of α-(3-R-1-adamantyl)sulfoacetic acids and their derivatives

By sulfonation of 3-R-1-adamantylacetic acids 1 with H₂SO₄ in trifluoroacetic anhydride (TFAA), the previously unknown α-(3-R-adamantyl)sulfoacetic acids 2 were obtained. In the case of 1-adamantylacetic acid 1a, the use of ～1 equiv of H₂SO₄ led to only 1-adamantylacetic acid 2a, while with an excess of the reactant the hydroxylation of the adamantane tertiary C–H bond also occurred. It is assumed that the bis(trifluoroacetyl)sulfate generated in situ from H₂SO₄ and TFAA is responsible both for sulfonation and oxidation steps. The adamantylated sulfoacetic acids were used for the preparation of a series of derivatives by modifications of carboxylic, sulfonic acid, and tertiary adamantane OH-groups. Due to the use of TFAA as a medium, a series of derivatives of sulfoacetic acids was obtained directly from acids 1 within one-pot procedures. Some of the synthesized compounds possess anti-HSV activity.     

Theoretical study on tetrazole and its derivatives (3) MP2 and thermodynamic calculations of amino derivatives of tetrazole

Fully optimized geometries and electronic structures of amino derivatives of tetrazole are obtained at MP2/6-31G* level. The tetrazole rings are planar and aromatic for all the amino derivatives of tetrazole. The amino group is not co-planar with the ring and its conformation is mainly determined by the lone pair electronic repulsion between the substituent and the ring. N(4) atom is more negatively charged and is the most probable coordination site. The energy gaps between LUMOs and HOMOs of 2H-aminotetrazoles and C-aminotetrazole neutrals are smaller than those of the corresponding 1H-isomers and N-aminotetrazole neutrals respectively. The IR frequencies, thermodynamic properties and temperature-dependent functions for heat capacities in the form (a bT cT2) in the 300-1000K range are reported.     

Chromogenic derivatives of new bis(phenylhydrazono-1H-tetrazol-5-yl-acetonitriles) – synthesis and properties

Derivatives of bis(phenylhydrazono-1H-tetrazol-5-yl-acetonitriles) with oxygen and sulphur atoms in the structure of aliphatic chains were successfully synthesised. The correlation between the ligand structure and its complexation properties was investigated by absorption spectroscopy. The formation of complexes of presented compounds with metal cations (Cu²⁺, Ni²⁺, Zn²⁺, Co²⁺, Fe²⁺ and Pb²⁺) was studied. Ligands 5–8 were additionally applied as ion carriers in ion-selective membrane electrodes. Membranes of ion-selective electrodes doped with these ligands are selective to Cu²⁺ and Pb²⁺ cations.     

Synthesis and characterization of adducts of p-azidostyrene derivatives to fullerene C_(60)

Fullerene C60 reacted with p-azidostyrene derivatives in refluxing chlorobenzene,yielding monoadducts 2a and 2d as well as diadduct 2c with aziridine structure at 6/6-ring junctions.Experimental results showed that the addition of the second azide to the monoadduct was regioselective.The diadduct,of Cs symmetry in C60 moiety,was unstable by opening to be 1,6-imido[10]annulene structure.     

3,4-Bis(α-nitroalkyl-ONN-azoxy)furazans and some of their derivatives

Reaction of pseudonitroles and their derivatives with diaminofurazan in the presence of dibromoisocyanuric acid (DBI) resulted in symmetrical 3,4-bis(-nitroalkyl-ONN-azoxy)-furazans or their derivatives. For the synthesis of bis(nitroalkyl-ONN-azoxy)furazans bearing various a-nitroalkyl-ONN-azoxy groups, the method based on the reaction of ??-nitronitroso compounds with 3-amino-4-(nitroalkyl)-ONN-azoxy)furazans (in the presence of DBI) was developed. Synthetic procedures towards aforementioned compounds with nitromethyl-, dibromonitromethyl-, trinitromethyl-ONN-azoxy and other groups were described.     

Cu(I)-catalyzed α-alkylation of ketones with styrene derivatives

α-Alkylation of ketones with styrene derivatives was developed using a mesitylcopper-dppp complex as a soft Brønsted base catalyst. No waste derived from the alkylating reagent was produced in this catalytic alkylation reaction. The bisphosphine ligand structure, as well as the reaction solvent, had profound effects on catalyst activity. The reaction proceeded under mild conditions from a range of ketones and styrene derivatives. The present catalysis is especially useful for the selective mono-alkylation of ketones.