Ring contraction of 1,3-bis(5-bromopentyl)alloxazine

The reaction of 1,3-bis(5-bromopentyl)alloxazine with ethylamine in propan-2-ol resulted in replacement of the terminal bromine atoms by ethylamino groups and was accompanied by contraction of the pyrimidine ring so that the products were 1,3-bis[5-(ethylamino)pentyl]alloxazine and 1,3-bis[5-(ethylamino)-pentyl]imidazo[4,5-b]quinoxalin-2-one.     

Synthesis of 1,3-bis(acetylacetonyloxy)- and 1,3-bis(benzoylacetonyloxy)benzene and their complexation with lanthanide ions

Claisen condensation of 1,3-bis(methoxycarbonylmethoxy)benzene with acetone and acetophenone afforded new chelating ligands consisting of two β-diketonate fragments, viz., 1,3-bis(acetylacetonyloxy)benzene and 1,3-bis(benzoylacetonyloxy)benzene, which are linked to each other through the resorcinol spacer. In the crystal, 1,3-bis(acetylacetonyloxy)benzene, unlike the starting ester, adopts a planar conformation and exists in the enol form. The acidities of these compounds and their complexation with lanthanide ions in aqueous ethanolic solutions were studied by pH-potentiometry. Depending on the concentration conditions and pH, the La³⁺, Gd³⁺, and Lu³⁺ ions form 1 : 1, 1 : 2, or 1 : 3 complexes with bis(β-diketones). The stability of the complexes increases as the atomic number of the lanthanide increases (La³⁺ < Gd³⁺ ≤ Lu³⁺). The complexation constants and selectivity of complexation substantially increase with increasing degree of deprotonation of the ligands, which indicates that both chelate groups of the ligands are simultaneously involved in coordination. The Ph substituents in bis(β-diketone) have a considerable effect on the composition and stability of complexes with lanthanide ions due to additional noncovalent inner-sphere interactions.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 614–622, March, 2005.     

Gold(III) extraction by 1,3-Bis(2′-acetoxymethylthiobutyl-3′-thiobutylpropyl)-6-methyluracyl from hydrochloric acid solutions

Gold(III) extraction by 1,3-bis(2′-acetoxymethylthiobutyl-3′-thiobutylpropyl)-6-methyluracyl from 0.5 M HCl solutions to chloroform is studied. The reagent has a high efficiency, separates gold(III) ions from the sum of nonprecious and ferrous metals, and can be repeatedly used after stripping. The extraction mechanism is solvation, with Au-S coordination bonds formed with all sulfur atoms of the reagent; the solvation number changes from 1 to 0.25 with increasing gold(III) aqueous concentration.     

5-(取代萘基)乙内酰脲的合成

在酸催化下,2－萘酚、1－溴－2羟基萘分别与尿囊素反应制得5－（2′-羟基－1′-萘基）乙内酰脲（收率81．8％）和5－（5′-溴－6′－羟基－2′－萘基）乙内酰脲（收率52．3％）。     

Phospha-s-triazines. IV. Degradation studies of 1-diarylphospha-3,5-bis(perfluoroaliphatic)-2,4,6-triazines and 1,3,-bis(diarylphospha)-5-perfluoroaliphatic-2,4,6-triazines

Thermal and thermal oxidative stability evaluations were performed on mono- and diphospha-s-triazines at 235 and 316°C using sealed Pyrex ampoules. The specific compounds studied were: 1-diphenylphospa-3,5-bis(perfluoro-n-heptyl)-2,4,6-triazine, 1-diphenylphospha-3,5-bis(perfluoro-alkylether)-2,4,6-triazines, their respective pentafluorophenyl analogues, 1,3-bis(diphenylphospha)-5-perfluoro-n-heptyl-2,4,6-triazine and 1,3-bis(diphenylphospha)-5-perfluoroalkylether-2,4,6-triazine. All the compounds wherein phenyl groups were present on the phosphorous exhibited good thermal stability up to 316°C; the analogous pentafluorophenyl substituted materials were degraded extensively at these temperatures. The oxidative stability of both the mono- and diphospha-s-triazines was excellent at 235°C, but at 316°C some degradation was observed. This was more pronounced in compounds containing the perfluoroalkyl moiety on carbon than in the perfluoroalkylether substituted members of the series.     

Synthesis and characterization of functionalized 1,3-bis(2- alkyltetrazol-5-yl)triazenes

A series of 1,3-bis(2-alkyltetrazol-5-yl)triazenes have been synthesized in high yields by treatment of sodium nitrite and hydrochloric acid with substituted-5-aminotetrazoles. All compounds were fully characterized using IR spectroscopy,~1H NMR and~(13) C NMR spectroscopy and high resolution mass spectrometer(HRMS). Most of these triazenes exhibit good detonation performance comparable with TNT and low melting points ranging from 81°C to 106°C, which are suitable for melt-cast explosives.Among these compounds, 1,3-bis(2-azidoethyltetrazol-5-yl)triazene(2g) displays a low melting point(106°C), moderate onset decomposition temperature(183°C) and good detonation performance(D:7087 m/s; P: 17.6 GPa).     

Reaction of 1,3-bis(η5-cyclopentadienyldicarbonyliron)-1-cyano-2,4-diphenyl-1,3-butadiene with group-VI metal carbonyls

Conclusions The reaction of the binuclear complex HPhC=C[Fe(CO)₂Cp]-C(Ph)=C[Fe(CO)₂Cp]CN with M-(CO)₅ ·THF (M=Cr, Mo, W) gave new trinuclear heterometallic -complexes, in which the M(CO)₅ fragments are coordinated at the nitrile group nitrogen.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2378–2331, October, 1987.     

Coammonolysis of 1,3-bis(chlorodimethylsilyl)-2,2,4,4-tetramethylcyclodisilazane with organomonochlorosilanes

Coammonolysis of 1,3-bis(chlorodimethylsilyl)-2,2,4,4-tetramethylcyclodisilazane with organomonochlorosilanes in toluene was studied. The reaction direction and product composition depend on the nature of the organic radical in organomonochlorosilanes and on the reaction temperature.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 10, 2004, pp. 1631–1638.Original Russian Text Copyright © 2004 by Varezhkin, Mikhailova, Krasnova, Chernyshev.This revised version was published online in April 2005 with a corrected cover date.     

Synthesis and reactions of 2-chloro-1,3-bis(trimethylsilyloxy)-1,3-butadienes

The reaction of 2-chloro-1,3-bis(trimethylsilyloxy)-1,3-butadienes with various electrophiles allows a convenient synthesis of chlorinated molecules which are not readily available by other methods.     

(Z,Z)-2,3-bis(trimethylsilyl)-1,4-dibromo- and 2,3-bis(trimethylsilyl)-1,1,4,4-tetrabromobuta-1,3-dienes. Synthesis and Diels-Alder reactions.

The two title compounds (1,2) have been prepared and some Diels-Alder reactions investigated.     

2-芳基-(4S,5S)-4,5-双(胺甲酰基)-1,3-二氧戊环的合成

以D-酒石酸二乙酯和芳香醛为原料,经缩醛化、氨解两步反应合成了15个未见文献报道的适合工业化生产庚铂类似物的关键中间体——2-芳基-(4S,5S)-4,5-双(胺甲酰基)-1,3-二氧戊环,产率49%～70%,其结构经1HNMR和MS表征。     

Molecular structure of 1,3-bis(dimethylamino)-2,2,3,4-tetrachloro-1,3-diphosphacyclobutene

Institute of Organic Chemistry, Ukrainian Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 33, No. 5, pp. 156–158, September–October, 1992.     

New copper(II) coordination compounds with 1,3-bis(5-(pyridin-2-yl)-1,2,4-triazol-3-yl)propane

Two new copper(II) complexes with 1,3-bis(5-(pyridin-2-yl)-1,2,4-triazol-3-yl)propane (H₂L), [Cu₂(HL)Cl₃] · H₂O (I) and [Cu(H₂L)](ClO₄)₂ (II), were described. The compounds were characterized by elemental analysis, IR spectroscopy, and magnetochemical data. According to X-ray diffraction data (CIF files CCDC nos. 1497511 (I), 1497512 (II)), complex I is binuclear and the metal cations are bound by the nitrogen atoms of the triazole ring and by the chloride anion. Complex II is mononuclear. Analysis of the temperature dependence of the magnetic susceptibility of I attests to the antiferromagnetic coupling of paramagnetic centers (–2J = 18 cm^–1). Exchange channels are analyzed by means of density functional theory (B3LYP/6-311G(d)) using the broken symmetry approach.     

New Chiral Diamines of the Dioxolane Series: (+)-(4S,5S)-2,2-Dimethyl-4,5-bis(diphenylaminomethyl)- 1,3-dioxolane and (+)-(4S,5S)-2,2-Dimethyl-4,5-bis(methyl- aminomethyl)-1,3-dioxolane

The reaction of sodium diphenylamide with 2,2-dimethyl-4,5-bis(tosyloxymethyl)-1,3-dioxolane gave (+)-(4S,5S)-2,2-dimethyl-4,5-bis(diphenylaminomethyl)-1,3-dioxolane, which was brought into complex formation with cobalt chloride. Treatment of 2,2-dimethyl-4,5-bis(tosyloxymethyl)-1,3-dioxolane with sodium N-methylanilide resulted in cleavage of the SÄO bond in the p-toluenesulfonate moiety with formation of N-methyl-N-phenyl-p-toluenesulfonamide and 4,5-bis(hydroxymethyl)-2,2-dimethyl-1,3-dioxolane disodium salt. Diethyl (4R,5R)-2,2-dimethyl-1,3-dioxolane-4,5-dicarboxylate reacted with methylamine to give the corresponding dicarboxamide which was reduced with lithium aluminum hydride to (4S,5S)-2,2-dimethyl-4,5-bis(methylaminomethyl)-1,3-dioxolane having chiral carbon and nitrogen atoms.     

Convenient synthesis of （4R,5R）-4,5-bis（aminomethyl）-2-isopropyl- 1,3-dioxolane

A convenient approach for the preparation of (4R,5R)-4,5-bis(aminomethyl)-2-isopropyl-1,3-dioxolane is described. The target compound via two steps is synthesized from diethyl-2,3-O-isobutylidene-D-tartrate, through ammonolysis and reduction.