Conversions of 2-thioxo-1,3-dithiol-4,5-dicarboxylic acid dimethyl ester — The path to a new heterocyclic system, (4H,6H)-1,3-dithiolo[4,5-d]pyrimidine-2,5,7-trione and 5,6-dimercaptouracil derivatives

The conversions of 2-thioxo-1,3-dithiol-4,5-dicarboxylic acid methyl ester into anhydride, mono- and diamide, and monoamide methyl ester were demonstrated. The new heterocyclic system, (4H,6H)-1,3-dithiolo[4,5-d]pyrimidine-2,5,7-trione, was obtained by oxidative rearrangement-cyclization of 2-oxo-1,3-dithiol-4,5-dicarboxylic acid diamide with phenyliodosyl(hydroxy)tosylate and used to synthesize previously unknown 5,6-dimercaptouracil derivatives, including nickel dithiolene complex.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1270–1275, September, 1992.     

Synthesis and several transformations of sulfides of the thiophene series

Several new N-substituted 2,5-bis(mercapto)-3,4-bis(iminomethyl)thiophenes, which are new tetradentate ligands of the thiophene series, were obtained by the reaction of primary amines with the product formed during the successive action of four equivalents of sodium in liquid ammonia and HCl on the tetraethylacetal of 2,5-bis(methylmercapto)-3,4-thiophenedialdehyde.For Communication XXII, see [4].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1323–1325, October, 1970.     

The transformations of fluoroalkyl-containing 2-arylhydrazono-1,3-dicarbonyl compounds with methylamine

Fluoroalkylated 1,2,3-triketone 2-arylhydrazones and 2-arylhydrazono-3-oxo esters react variously with methylamine depending on the structure of the fluorinated substituent. 2-Arylhydrazono-1,3-dicarbonyl compounds having “short” fluoroalkyl substituents condense with methylamine at the carbonyl group attached to the non-fluorinated substituent whereas ones containing a lengthy polyfluoroalkyl substituent undergo haloformic cleavage as a result of the amine addition at the carbonyl group bearing such a substituent. The resulting 2-arylazo-3-(N-methyl)amino-1-polyfluoroket-2-en-1-ones and 1-(N-methyl)amino-2-arylhydrazono-3-fluoroalkyl-3-oxopropanamides have complexing properties, and they can bind to nickel(II) and copper(II) ions. Nickel chelates can be obtained by a three-component condensation of 2-arylhydrazono-1,3-dicarbonyl compounds and methylamine in the presence of nickel(II) cations.     

Synthesis and reactions of heterocyclic compounds

5-Azido-2-methylbenzthiazole, 6-azido-1, 2-dimethyl-, and 5-azido-2-methyl-1-phenylbenzimidazoles were prepared. By the reactions of these azides with alkyl halides the quaternary slats based on the cyanine dyes were obtained.     

Polarographic reduction of adenine and its 9-(α,ω-dihydroxy-2-alkyl) derivatives

The polarographic reduction of adenine and its 9-(,)-dihydroxy-2-alkyl) derivatives on a short-period mercury electrode in strongly acidic media is determined by the rate of diffusion of the corresponding cations and, at pH values that exceed the pK_a values, by the kinetics of surface protonation of the uncharged molecules; this was proved by the dependence of the limiting current on the height of the mercury column, the temperature, and the depolarizer concentration. The polarographic reduction of adenine, adenosine, 9-(,-di-hydroxy-2-alkyl)adenines, and the corresponding phosphates in acidic media proceeds with the loss of sic electrons per molecule. The similar trends of the change in the half-wave potentials and the numerical pK_a values is associated with the fact that the site of protonation is simultaneously the site of nucleophilic attack by the electron during electrical reduction.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1675–1678, December, 1977.     

Effect of the morphology of polyethylene glycol esters on the distribution of C1–C4 carboxylic acids in the gas phase-sorbent system

The effect of the morphology of polymer films on the distribution of volatile C₁–C₄ carboxylic acids in the sorbent-gas system is discussed. The efficiency of sorption of vapors of formic, acetic, propionic, and butyric acids on films of polyethylene glycol esters of various structures formed on the electrodes of a piezoquartz resonator by means of static evaporation of a drop and immersion of the resonator into a sorbent solution is evaluated.     

Crystallization impedance in the case of D.C. superposition

An expression for the impedance frequency dependence in the case of d.c. superposition has been derived and analyzed for the crystallization process of metals taking into account the two-dimensional diffusion of ions in solution and the surface diffusion of adatoms and using the simplest surface model with parallel step lines. It is shown that in the general case it is impossible to present the crystallization impedance as the sum of the surface diffusion impedance and the Warburg impedance. It has been found that in the case of anode polarization an unusual effect of the impedance increasing with agitation intensity takes place which is typical of this mechanism. Possible methods for determination of the model parameters from impedance measurements are discussed. The authors suggest an iteration procedure which permits to determine all the parameters of the model under consideration including the surface diffusion coefficient of adatoms and the spacing between the growth step lines.     

Mass spectra of permethylates of spirostanol tetraosides

The design of the new MKh 1310 mass spectrometer with double focusing permits the recording of the spectra of sparingly volatile natural compounds with molecular weights of up to 1700 and, in particular, the permethylates and peracetates of spirostanol and furostanol saponins. The results are given of an investigation of the mass spectra of five spirostanol tetraosides in the form of their permethylates. The spectra contain the peaks of the molecular ions and of the products of their decomposition at the glycosidic bonds. The most important feature of the spectra is the fragmentation of the skeletons of the terminal saccharide residues starting directly from M⁺ in directions close to the directions of decomposition of the nonreducing unit of permethylates of oligosaccharides. The origin of the ions (M -191)⁺, (M - 175)⁺, (M - 162)⁺, (M - 147)⁺, (M - 131)⁺, (M - 118)⁺, and (M - 102)⁺ arising this way have been confirmed by measurements of their elementary compositions.     

16-Demethoxymethyllycaconitine,a new norditerpenoid alkaloid from Delphinium cuneatum

A new norditerpenoid alkaloid has been isolated from the roots of Delphinium cuneatum. On the basis of ¹H, ¹³C NMR, IR, and mass spectra, the structure of the alkaloid was established as 1,6,14-trimethoxy-7,8-dihydroxy-18-(2-methyl)succinylanthranoyloxyaconane (16-demethoxymethyllycaconitine). The roots of Delphinium cuneatum also contain the known alkaloid methyllycaconitine and N,N"-di(methoxycarbonyl)-3,4-diaminotoluene.     

Berberis alkaloids. XXI. Intebrine — A new N-benzylisoquinoline alkaloid from Berberis integerrima

A new N-benzylisoquinoline alkaloid — intebrine, with the composition C₂₀H₁₉NO₇ — has been isolated fromBerberis integerrima Bunge. The spatial structure of intebrine has been reliably determined by the x-ray structural method (diffractometer, CuK radiation, 972 reflections, direct method, R=0.048). Its chemical behavior, spectral characteristics, and mass-spectrometric fragmentation under electrom impact have been studied.Andizhan State Medical Institute. Institute of the Chemistry of Plant Substances, Uzbekistan Republic Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedeninii, No. 1, pp. 65–70, January–February, 1993.