Synthesis of unsubstituted 1,3,5-triazabicyclo[3.1.0]hexane

Unsubstituted 1,3,5-triazabicyclo[3.1.0]hexane has been syntesized for the first time by treating a Henry solution with NaOCl.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1665–1666, September, 1993.     

Medium Effect on the Rotational Isomerism in 1,3,5-Triacetylbenzene

Summary. The optimal geometries, energies, polarities, infrared frequencies, and intensities of the non-polar and polar conformers of 1,3,5-triacetylbenzene were calculated using DFT/B3LYP/6-311G** and semi-empirical (AM1 and PM3) methods. All the methods revealed that the non-polar conformer prevails in vacuum. The infrared spectra in the solid state, in Ar matrix, and in liquid solutions as well as the dipole moments of 1,3,5-triacetylbenzene in many solvents show the distinct influence of the environment on the non-polar conformer ⇌ polar conformer equilibrium. The effect of solvent polarity on the standard Gibbs energy of this conformational equilibrium is quantitatively discussed in terms of the continuum-homogenous dielectric model.     

Thermal decomposition of 2,4,6-trinitrotoluene in melt and solutions

Thermal decomposition of 2,4,6-trinitrotoluene in the temperature range from 200 to 340 °C in melt and in solutions was studied. The main features of the process (high initial rates, activation energies lower than those in the gaseous phase, a higher acceleration at the catalytic stage, and the effect of nonpolar solvents on initial rates) are explained in terms of a kinetic scheme corresponding to a degenerate branched chain reaction.Translated fromIzyestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 266–271, February, 1995.     

Synthesis,structures, and properties of bis(4,6-disubstituted 1,3,5-triazin-2-yl) ethers

Reactions of (4,6-disubstituted 1,3,5-triazin-2-yl)trimethylammonium chlorides with glycine sodium salt in the presence of Et₃N afforded bis(triazin-2-yl) ethers instead of the expected triazinylaminoacetic acids. The structures of the resulting compounds were established by the independent synthesis, spectroscopic data, and X-ray diffraction analysis.     

Regioselective synthesis of cis- and trans-2,4,5-triarylimidazolines and 2,4,5-triarylimidazoles from available reagents

Novel data were obtained concerning the reaction of aromatic aldehydes with ammonia. A preparative method for the synthesis of new substituted 1,3,5-triaryl-2,4-diazapenta-1,4-dienes was developed. These products are the starting reactants for syntheses of cis- and trans-2,4,5-triaryl-2-imidazolines and 2,4,5-triarylimidazoles.     

Molecular conformations and harmonic force field of 1,3,5-benzenetriol molecule from ab initio and density functional theory investigations

The molecular conformers of the molecule 1,3,5-benzenetriol have been studied by ab initio and density functional methods to determine optimized equilibrium geometries, harmonic vibrational frequencies and relative stability. The results of the quantum-chemical calculations have been used to investigate the functional theory-infrared (FT-IR) spectrum of the 1,3,5-benzenetriol vapors trapped in Ar matrix at 12 K.     

Chemistry of 2,4,6-trinitrobenzonitrile. 1. Nitro group substitution in 2,4,6-trinitrobenzonitrile under the action of anionic nucleophiles. Factors favoring substitution of the ortho-nitro group

The direction of the nitro group substitution (the ratio of the ortho/para substitution) in 2,4,6-trinitrobenzonitrile under the action of anionic nucleophiles (MeO^–, RS^–, and N₃ ^–) as well as of HCl was studied. The factors favoring ortho substitution were revealed.     

The Mannich reaction in the synthesis of N,S-containing heterocycles 6. New approaches to the synthesis of pyrimido[4,3-b][1,3,5]thiadiazine derivatives

Aminomethylation of 2,6-diamino-4-aryl-4H-thiopyran-3,5-dicarbonitriles in the Mannich reaction with p-toluidine and formaldehyde unexpectedly gave pyrimido[4,3-b][1,3,5]thiadiazine derivatives. The same compounds were obtained in an independent way involving a multicomponent cascade condensation of aromatic aldehydes, cyanothioacetamide, p-toluidine, and formaldehyde. For Part 5, see Izv. Akad. Nauk, Ser. Khim., 2007, 1384 [Russ. Chem. Bull., Int. Ed., 2007, 56, 1437]. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1420–1422, July, 2007.     

Novel generation of selenoaldehydes through stannic chloride-induced unsymmetrical C-Se bond cleavage of bis(N,N-dimethylcarbamoylseleno)methanes

Treatment of a benzene or a CH₂Cl₂ solution of bis(N,N-dimethylcarbamoylseleno)methanes with SnCl₄ afforded β-1,3,5-triselenanes, and the key intermediates, acylselonium ions and selenoaldehydes, were successfully trapped by using allyltrimethylsilane or 2,3-dimethyl-1,3-butadiene to obtain the allylation products or the cycloadducts, respectively.