One-pot synthesis of 1,5,3-oxathiazepanes via the three-component condensation of primary amines,formaldehyde and 2-mercaptoethanol

The three-component condensation reaction of primary amines, formaldehyde and 2-mercaptoethanol using salts of transition and rare earth metals as catalysts was developed to obtain a new 7-membered heterocyclic structural building block, 1,5,3-oxathiazepanes, in good to excellent yields. The structure of the heterocyclic fragment was confirmed by NMR spectroscopy.     

Synthesis, crystal structure, and antitumor activity of the cadmium dichloride complex with semicarbazide

The chelate cadmium dichloride complex with semicarbazide was synthesized. The use of this complex in the cytostatic combination therapy together with cyclophosphamide results in 67% survival of mice and a threefold increase in the average life span of survivors with P-388 leukemia.     

Relationship between the spectral properties of solutions of borofluoride complex of alkylated dipyrromethene and the physicochemical parameters of solvents

Spectral and photophysical characteristics of borofluoride complex of alkylated dipyrromethene (Bodipy) are determined by means of absorption and fluorescence electron spectroscopy in various organic solvents. Dependences of the spectral and photophysical characteristics of Bodipy solutions vs. the physico-chemical parameters of solvents are obtained by linear regression analysis and the contribution from each parameter to the property under study is determined. It is established that the negative solvatochromic effect is intrinsic for Bodipy. It is concluded that specific interactions contribute substantially to the properties of the chromophore, which are determined by the electron donor properties of the solvent.     

Do modern Russian schools provide education or training?

The concepts of “education” and “training” are sometimes considered synonymous. However, it is not true, as education is a result of training always requiring systematization of the acquired knowledge. Students of non-chemical schools have not been receiving education in chemistry in the course of training in chemistry for a long time already. The reason is poorly thought-out reforms of the educational system taking place for the last 10–15 years. The lack of sufficient chemistry education prevents students from mastering chemistry in higher educational institutions. The situation is aggravated by the transition of higher educational institutions to a two-step “bachelor-master” system.     

Non-empirical and DFT calculations of <Superscript>19</Superscript>F and <Superscript>13</Superscript>C chemical shifts in the NMR spectra of substituted pentafluorobenzenes

Chemical shifts in ¹⁹F and ¹³C NMR spectra of substituted pentafluorobenzenes are calculated by Hartree-Fock and density functional theory methods. The calculated values are compared with the experimental data known from the literature. It is shown that chemical shifts in non-polar solvents can be predicted sufficiently accurately by the GIAO-DFT(PBE/L22) method. This method is used to predict the ¹⁹F and ¹³C chemical shifts of a heptafluorobenzyl cation in the SbF₅ medium. The best agreement between the calculated and experimental values is achieved when the counterion effect is taken into account.     

Dihalogenoformals

Conclusions The interaction of the thionocarbonates of fluoro- and nitro-containing alcohols with chlorinating (Cl₂, SO₂Cl₂) and fluorinating (F₂, AgF, SbF₅) agents gave the dichloro- and difluorohalogenoformals of the corresponding alcohols.For previous communication, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 113–116, January, 1989.The authors express their thanks to G. V. Lagodzinskii, L. N. Erofeev, and A. E. Sosikov for the taking of the NMR spectra.     

Hydroxamic acids: synthesis and adjuvant activity in combinatorial anticancer therapy

Russian Chemical Bulletin - Monoand disubstituted N-hydroxyamides of dicarboxylic acids were prepared by reaction of dicarboxylic acids or acid anhydrides with hydroxylamine. The use of these...