Study of N,N′-dihydroxyethyldithiooxamide by X-ray diffraction,u.v.-vis,NMR, Raman and i.r. spectroscopy

The vibrational, NMR and electronic spectra of HO(CH₂)_xNHCSCSNH(CH₂)_xOH (x = 2,3,5,6) are discussed. A vibrational analysis has been proposed for the N,N′-dihydroxyethyldithiooxamide (x = 2) and its deuterated (NH/ND, OH/OD) analogue. The structure of N,N′-DHEDTO was solved by X-ray analysis. M_r = 208, monoclinic, space group P2₁/n, a = 9.8800(5) Å, b = 11.3260(7) Å, c = 9.7806(8) Å, β = 119.366(5)°, V = 953.8 ų, Z = 4, Dc = 1.365 Mgm⁻¹,μ(CuKα) = 0.47 mm⁻¹, F(000) = 440.00, T = 300 K. Final conventional R-factor = 0.036, R_w = 0.037, for 1608 unique reflections with I > 3.σ(I) out of 1800 measurements. The structure was solved using the automatic programs PATSYS and DIRDIF. The two νOH bands in the i.r. spectrum are in agreement with the crystallographic structure, which proposes that the unit cell of the compound consists of two independent molecules.     

Arylsulfimide Polymers. IV. Prototype Transamidations–A Comparison of the Reactions of Benzamides,Benzimides, Sulfonamides,Sulfonimides, and Saccharins

Transamidation reactions of nonpolymerizing systems involving benzamides, phthalimides, arylsulfonamides, benzenedisulfonamides and -disulfonim-ides, and saccharins are described. The study includes reactions of both N-substituted and unsubstituted amides and imides with anilines and aniline hydrochlorides. An evaluation of the results of these reactions, aimed at establishing the optimum conditions for transamidations in polymerizing systems, is also presented.     

Synthesis and Properties of Azoles and Their Derivatives. 47. Regioselectivity, Stereoselectivity and Kinetics of [2+3] Cycloaddition Reaction of Z-C,N-Diphenylnitrone with E-β-Nitrostyrenes

The [2+3] cycloaddition of Z-C,N-diphenylnitrone with E--nitrostyrenes leads to (3SR, 4SR, 5SR)- and (3SR, 4RS, 5RS)-2,3-diphenyl-4-nitro-5-arylisoxazolidines as the only reaction products. The kinetics of the reaction was studied by using the HPLC method. It was found that total rate constants increase with increasing substituent Hammett -constants. The substituent effect is rationalized in terms of FMO theory.     

Aminoamidines. 5. Synthesis and acetylation of N,N1,N2-triaryl-substituted β-aminoamidines

Triaryl-substituted -aminoamidines were obtained by the reaction of ,-unsaturated N-arylimidoyl chlorides with arylamines. Acylation of the products gave the products from monosubstitution at the -amino group. Triaryl-substituted -aminoamidines react with phosgene and with oxalyl chloride to form 4-aryliminoperhydropyrimidin-2-ones and 5-aryliminoperhydro-1,4-diazepine-2,3-diones, respectively.For previous communication, see [1].A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' Scientific Center, Russian Academy of Sciences, 420083 Kazan'. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2633–2642, November, 1992.     

Structure and energy study of β-diketonates. XV. Composition of superheated vapors and structure of monomeric molecules of <Emphasis Type="Italic">tris</Emphasis>-hexafluoroacetylacetonates of dysprosium,holmium, erbium,and ytterbium

The molecular structure of tris-hexafluoroacetylacetonates of dysprosium, holmium, erbium, and ytterbium (M(hfa)₃, M = Dy, Ho, Er, Yb) is studied in the framework of synchronous electron diffraction and massspectrometric experiment and also quantum-chemically. For all M(hfa)₃ complexes structural parameters r _a , r _g , and r _h1 are found. It is established that the coordination polyhedron LnO₆ has a configuration of D ₃ symmetry. In experiments on superheated vapors of Dy(hfa)₃, Ho(hfa)₃, and Yb(hfa)₃ the molecular forms present in the vapor at different degrees of superheat are determined.     

Experimental thermochemical study of the enthalpies of formation and sublimation of isonicotinamide,picolinamide, nicotinamide,isonicotinamideN-oxide,and nicotinamideN-oxide. The dissociation enthalpies of the N–O bonds

The standard (p ^∘  =  0.1MPa) molar enthalpies of combustion in oxygen, at T =  298.15 K, for crystalline picolinamide (2-NH₂COPy), nicotinamide (3-NH₂COPy), isonicotinamide (4-NH₂COPy), nicotinamide N -oxide (3- NH₂COPyNO), and isonicotinamide N - oxide (4-NH₂COPyNO) were measured by static-bomb calorimetry. These values were used to derive the standard molar enthalpies of formation of the crystalline compounds. The standard molar enthalpies of sublimation, at T =  298.15 K, for the three pyridinecarboxamide isomers were measured by microcalorimetry and the standard molar enthalpies of sublimation for the two pyridinecarboxamide N -oxide compounds were measured by a mass-loss effusion technique. From the enthalpies of formation of the gaseous compounds, the molar dissociation enthalpies D_m^oof the (N ⁺ – O ⁻ ) covalent bonds were derived. Comparison has been made with D_m^o(N–O) values in pyridine N -oxide derivatives.     

A review of: “The Effects of Hostile Environments on Coattings and Plastics,Acs. D. P. Garner and G. A. Stahl (Editors): Symposium Series 229, American Chemical Society,Washington, D.C., 1983, 339 pp., U.S. and Canada $47.95, export $57.95.”

Rh‐catalyzed polymerization of a new N‐propargylamide monomer having a galactose residue was investigated. The polymerization proceeded in a mixed solvent of THF and water to produce the galactose‐carrying poly(N‐propargylamide) consisting of cis‐isomer. The copolymerization of the monomer with the N‐propargylamide having the alkyl chain was also carried out.     

Isolation and Structure of 1-Deoxybaccatin VI from the Root of Taxus chinensis, Rehd. var. mairei

Deoxybaccatin Ⅵ (4α,7β,9α,10β,13α-penta-acetoxy-2α-benzoyloxy-5β,20-epoxytax-11-ene) was isolated from the roots of Taxus chinensis, Rehd. var. mairei. The structural assignments of the compound were based on their spectral data, including 2D NMR experiments and chemical correlation. The X-ray crystallographic analysis of 1-deoxybaccatin Ⅵ provided unambiguous characterization for the structures. In the structure, the six-membered A ring exhibits boat conformation, the eight-membered B ring adopts boat-chair conformation, and the six-membered C ring exhibits a sofa conformation.