5(3)-Hydroxyisoxazolidin-3(5)-ones and 5-hydroxy-pyrazolidin-3-ones and their ring-chain tautomerism

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 280–281, February, 1991.     

Si5H3,Si5H6,Si5Li3及Si5Na3原子簇结构的理论研究

利用Gaussian-94计算程序中的B3LYP方法，在6—311 G(2d)6d基组下，对Si5，Si5H3，Si5H6，Si5Li3和Si5Na33原子簇的几何结构进行优化和频率计算．结果表明，Si5原子簇中最稳定的具有D3h对称性的结构中，位于同一平面上的3个Si原子确实具有剩余的成键能力，可以与3个H，Li，Na原子和6个H原子形成稳定的化合物．研究还发现，虽然H，Li和Na都属同一主族，但它们与Si5原子簇中Si原子的键连方式却不同，而且它们的加入，对Si5原子簇的“三角双锥”结构也有不同的影响．     

The syntheses of 5-amino-3-t-butylisothiazole and 3-amino-5-t-butylisothiazole

A general synthesis of 3-amino-3-alkylpropenenitriles is described. These intermediates are further transformed to 5-amino-3-alkylisothiazoles. Also described is the synthesis of the novel isomer, 3-amino-5-t-butyl-isothiazole.     

3-Aminomethyl-substituted 5-aminopropynylindoles

Conclusions Some 3-aminomethylindoles with an aminopropynyl grouping in the 5 position of the indole ring were obtained.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2380–2381, October, 1979.     

3-H-isoxazolin-5-ones

4-Alkyl and 4-phenyl isoxazolin-5-ones were prepared. The 4-alkyl compounds were found to isomerize easily to α-cyano carboxylic acids. The acidity and the tautomeric composition of the compounds prepared arc surveyed and compared to the results of the previous literature.     

Sm5Ga3

Single crystals of penta­samarium trigallium, Sm₅Ga₃, display tetra­gonal symmetry. The crystal structure was solved and refined in space group P4/ncc. The present work does not confirm the space group I4/mcm previously deduced from powder data measurements. One Sm atom is in a general position, and the other Sm atom and one of the Ga atoms are at sites with fourfold symmetry. The remaining Ga atom is at a site with twofold symmetry.     

5-Hydroxy-3-phenyl-5-vinyl-2-isoxazoline and 3-phenyl-5-vinylisoxazole: synthesis and reactivity

5-Hydroxy-3-phenyl-5-vinyl-2-isoxazoline has been synthesized by reacting benzonitrile oxide with the enolate ion of methyl vinyl ketone. From 5-hydroxy-5-vinyl-2-isoxazoline, 5-vinylisoxazole was then quantitatively obtained by dehydration-aromatization under acidic conditions. Similar results, though not quantitative, were also found by treatment in 2-propanol under basic conditions (i-PrOH/H₂O, Na₂CO₃, reflux). In contrast to 2-propanol, reactions performed in methanol (and, in part, those carried out in ethanol) revealed a more complex behaviour, the nucleophilic addition of ROH onto the vinyl group being mainly observed. Nucleophilic addition was also found with alkyllithiums. The mechanism of the nucleophilic addition is discussed. Epoxidation and further reaction with benzonitrile oxide of both 3-hydroxy-5-phenyl-5-vinyl-2-isoxazoline and 3-phenyl-5-vinylisoxazole are also described.     

Darstellung und Kristallstruktur von Ca5Hg3 und Sr5Cd3

Preparation and Crystal Structure of Ca₅Hg₃ and Sr₅Cd₃ Both the incongruently melting compounds, Ca₅Hg₃ and Sr₅Cd₃, have been synthesized from stoichiometric amounts of the pure elements. They crystallize with the Cr₅B₃ type of structure: space group I4/mcm, Z = 4; Ca₅Hg₃ (Sr₅Cd₃): a = 818.9(1) (871.7(1)) pm, c = 1 470.1(3) (1 660.1(3)) pm, c/a = 1.80 (1.90), R = 2.33% (2.97%). The most remarkable fragments are dumbbells X₂, which have interatomic distances only slightly longer than the sum of Pauling's covalent radii: Hg? Hg (Cd? Cd) = 306 (298) pm. The structure can be constructed by rhombic dodecahedra as the only constituent moieties. These rhombic dodecahedra are built up by eight Ca (Sr) atoms and six Hg (Cd) atoms and are furthermore centered by an additional Ca (Sr) atom. Along [001] the rhombic dodecahedra share common vertices, but along [110] they are interconnected via common triangular faces. This kind of face sharing is responsible for the short distances obtained between the polyhedra, which leads to the occurrence of the dumbbells mentioned above.     

Darstellung von 3-Amino-4-nitro-5-methylisoxazol aus 3-Amino-5-methylisoxazol

Zusammenfassung 3-Amino-5-methylisoxazol wird mit Bernsteinsäureanhydrid in 3-Succinimido-5-methylisoxazol übergeführt, welches sich mit Oleum und rauch. HNO₃ nitrieren läßt. Die Abnahme der Schutzgruppe zu 3-Amino-4-nitro-5-methylisoxazol erfolgt mit alkohol. HCl.

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Preparation of 3-amino-4-nitro-5-methylisoxazole from 3-amino-5-methylisoxazole

3-Amino-5-methylisoxazole is converted to 3-succinimido-5-methylisoxazole with succinic anhydride. The product can be nitrated with oleum and fuming HNO₃. Removal of the protective group yielding 3-amino-4-nitro-5-methylisoxazole is effected with alcoholic HCl.

     

Synthesis and Structure of 3-Aryl-2,4-dibenzoyl-5-hydroxy-5-methylcyclohexanones and 2-Benzoyl-5-hydroxy-5-methyl-3-phenylcyclohexanone

The reaction of benzoylacetone with aromatic aldehydes under basic catalysis conditions afforded 3-aryl-2,4-dibenzoyl-5-hydroxy-5-methylcyclohexanones. The reaction of benzoylacetone with benzalacetone led to the formation of 2-benzoyl-5-hydroxy-5-methyl-3-phenylcyclohexanone.     

Die Phasen Nb3Ga2, Ta5Ga3 und Ta5Al3Bx

Zusammenfassung Die Phasen Nb₃Ga₂, Ta₅Ga₃ und Ta₅Al₃B_x werden aus den Komponenten hergestellt. Nb₃Ga₂ kristallisiert im U₃Si₂-Typ, Ta₅Ga₃ hat Cr₅Br₃-Struktur (T 2) und Ta₅Al₃B_x ist mit Mn₅Si₃ (teilweise aufgefüllt) isotyp.     

Reaction of 3-Amino-5H- and 3-Amino-5-sulfanyl-1,2,4-triazoles with 1,2,4-Triazine-5-carbonitriles

Russian Journal of Organic Chemistry - 1,2,4-Triazines with an unsubstituted (1,2,4-triazol-3-yl)amine residue in the C5 position were synthesized by the solvent-free ipso-amination reaction...