Russian Chemical Bulletin最新文献

2-Azido-4-chloro-6-phenylpyrimidine-5-carbaldehyde was synthesized by the Vilsmeier–Haack reaction. In DMSO, it transforms into 7-oxo-5-phenyl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carbaldehyde and then undergoes isomerization recyclization into 6-benzoyltetrazolo[1,5-a]pyrimidin-7(4H)-one. The structures of the obtained compounds were determined by NMR spectroscopy and X-ray diffraction.

Nucleophilic ring-opening of 1,6,10,14-tetraoxatetraspiro[2.1.2⁵.1.2⁹.1.2¹³.1³]hexadecane, a cyclooctane structure spiro-fused with four oxirane fragments, under the action of sodium azide was studied. Depending on the relative configuration of stereocenters in the starting compound, the reaction proceeded as an intramolecular transannular cyclization with the formation of a 9-oxabicyclo[3.3.1]nonane skeleton or as an independent nucleophilic opening of the oxirane rings, leading to tetraazido tetraols of the cyclooctane series.

Non-annulated tetrazole-containing polynuclear compounds, in which heterocyclic fragments are bound by an acetamide linker were synthesized. The synthesis was accomplished by acylation of 2-hydrazinyl-4,6-dimethylpyrimidine, 4-amino-4H-1,2,4-triazol-3-thiol, 2-[(1-amino-1H-tetrazol-5-yl)thio]-N-tert-butylacetamide, 1-methyl-1H-tetrazol-5-amine, and 2-methyl-2H-tetrazol-5-amine with one key reagent, (5-phenyltetrazol-2-yl)acetyl chloride. Preliminary in silico studies showed the presence of the in vivo antidiabetic (diabetes 2 type) activity in N′-(4,6-dimethylpyrimidin-2-yl)-2-(5-phenyl-2H-tetrazol-2-yl)acetohydrazide. N-(3-Mercapto-4H-1,2,4-triazol-4-yl)-2-(5-phenyl-2H-tetrazol-2-yl)acetamide demonstrated minimal hypoglycemic activity in in vivo studies, at the same time, it showed pronounced activity as a drug for combating obesity.

Spirocyclic scaffolds have received increasing interest because of their wide use in medicinal chemistry and the need for designing new effective drugs on their basis. Electroorganic synthesis is an environmentally friendly method for the preparation of organic compounds because hazardous and toxic redox reagents are replaced by electric current and the overall energy costs are reduced. Modern methods for the electrosynthesis of spiro compounds and the prospects of their development are analyzed. The review summarizes the data on the types of electrochemical and electrocatalytic methods. The potential practical applications of these methods for the preparation of individual classes of spirocycles are discussed.

In the ¹H NMR spectra (DMSO-d₆) of 1,3-disubstituted ureas containing the 4,7,7-trimethyl-3-oxo-4-oxabicyclo[2.2.1]heptan-1-yl substituent, the signals for the CH₂—CH₂ moiety appear as an ADMP-type spin system consisting of four doublets of doublets of doublets with chemical shifts in the range from 1.54 to 2.80 ppm. The experiment in CD₃OD showed the disappearance of the signal at δ 2.80 and a change in the multiplicity of the other signals, which is indicative of the selective deuterium exchange of one of the four protons of the CH₂—CH₂ group for a deuterium atom. This allows the selective modification of compounds containing the oxacamphanyl moiety.

A synthesis of the quinazolin-4-one pharmacological agent methaqualone from N-(2-carboxyphenyl)oxalamide was developed. A new method for the reductive cyclization of 3-(2-nitrophenyl)quinazolin-4-ones to benzimidazo[2,1-b]quinazolin-12(6H)-ones, the 6-deoxo-6-aza analogs of natural alkaloid tryptanthrine, was suggested and new derivatives of poorly available quinoxalinoquinazolinone fused system were synthesized.

The mini-review covers the results of the authors on acetylene chemistry achieved within 2022. This unusual format was selected in order to assess the dynamics and effectiveness of the developed approaches in result/time coordinates and the prospects for further research in these areas. The review discusses new reactions of acetylene and its derivatives that generally take place in superbasic media, in which the dual reactivity of the carbon—carbon triple bond (i.e. its ability to exhibit both nucleophilic and electrophilic properties) is most pronounced. The discovered by us reactions are the atom economical (they do not produce side products), energy- and resource-saving (they proceed at room or slightly elevated temperature), do not require transition metal catalysts, and can be implemented using inexpensive available starting compounds.

On the basis of the Ti-catalyzed homocyclomagnesiation of terminal 1,2-dienes, an effective method for the synthesis of 1Z,5Z,9Z,13Z-tetraenes in high yields and high stereoselectivity has been developed. A new approach to the synthesis of allenes with substituents containing Z-double bonds has been elaborated.

Trimethyl orthoacetate (MeC(OMe)₃, TMOA) is a convenient reagent for both selective and complete O-methylation of the β-OH groups of sea urchin pigments such as spinazarin, spinochromes D and E, and echinochrome A. The reactions of these compounds with TMOA make it possible to furnish preparative amounts of 6-monomethyl ethers of spinochrome D and echinochrome A, 7-monomethyl ether (namakochrome) and 6,7-dimethyl ether of spinochrome E, which are difficult to prepare by other methods, and to carry out complete O-methylation of all discussed pigments. Among the known O-methylating agents, TMOA is most suitable for the preparative syntheses of methyl ethers of polyhydroxynaphthazarins.