Selective synthesis of 1,3-dialkyl-4-nitro-1,2,3-triazolium salts from 1-alkyl-4-nitro-1,2,3-triazoles and dialkyl sulfates

The process of alkylation of 1-alkyl-substituted 4-nitro-1,2,3-triazoles with dimethyl and diethyl sulfates has been studied. The structures of the N,N’-dialkyl-C-nitro-1,2,3-triazolium alkylsulfates and perchlorates has been confirmed by IR, ¹H and ¹³C NMR spectroscopy. Alkylation with an excess of dialkyl sulfate occurred regioselectively at N-3 with the formation of 1,3-dialkyl-4-nitro-1,2,3-triazolium salts, which is in agreement quantum-chemical calculations of the relative stability of the corresponding isomeric cations. The molecular and crystal structures of the first example of this type of salt – 1,3-diethyl-4-nitro-1,2,3-triazolium perchlorate – have been determined by X-ray crystallo-graphy. Nitrotriazolium salts with mixed alkyl substituents – 3-ethyl-1-methyl- and 1-ethyl-3-methyl-4-nitro-1,2,3-triazolium salts – have been synthesized an studied for the first time.     

Special features of the alkylation of 7-bromo-5-(2-chlorophenyl)- 3-hydroxy-1,2-dihydro-3h-1,4-benzo- diazepin-2-one with alkyl tosylates

On interacting 7-bromo-5-(2-chlorophenyl)-3-hydroxy-1,2-dihydro-3H-1,4-benzodiazepin-2-one with methyl, hexyl, dodecyl, and cetyl tosylates, 1-alkyl-7-bromo-5-(2-chlorophenyl)-1,2,4,5-tetrahydro-3H-1,4-benzodiazepin-2,3-diones, and 1-alkyl-7-bromo-5-(2-chlorophenyl)-3-hydroxy-1,2-dihydro-3H-1,4-benzodiazepin- 2-ones were obtained. Only the dione was formed in the case of hexyl tosylate. On alkylating with methyl tosylate only the 3-hydroxy derivative was formed. It was shown that at pH 14 the 1-cetyl and 1-dodecyl-3-hydroxy derivatives were completely converted into the corresponding diones. The molecular and crystal structures of the compounds were established by X-ray structural analysis.     

External Estimates for Reachable Sets of a Control System with Uncertainty and Combined Nonlinearity

The problem of estimating the trajectory tubes of a nonlinear control dynamic system with uncertainty in the initial data is studied. It is assumed that the dynamic system has a special structure in which the nonlinear terms are defined by quadratic forms in the state coordinates and the values of uncertain initial states and admissible controls are subject to ellipsoidal constraints. The matrix of the linear terms in the velocities of the system is not known exactly; it belongs to a given compact set in the corresponding space. Thus, the dynamics of the system is complicated by the presence of bilinear components in the righthand sides of the differential equations of the system. We consider a complicated case and generalize the author’s earlier results. More exactly, we assume the simultaneous presence in the dynamics of the system of bilinear functions and quadratic forms (without the assumption of their positive definiteness) and we also take into account the uncertainty in the initial data and the impact of the control actions, which may also be treated here as undefined additive disturbances. The presence of all these factors greatly complicates the study of the problem and requires an adequate analysis, which constitutes the main purpose of this study. The paper presents algorithms for estimating the reachable sets of a nonlinear control system of this type. The results are illustrated by examples.     

The Possibility of liquid-like and amorphous states existing in nano- and microregions of deformed metallic materials

The possibility of the periodic formation of a liquid-like state in nanoregions of highly nonequilibrium grain boundaries and other regions of defects in metallic materials upon superplastic deformation and intense plastic deformation is considered, based on the results from a thermodynamic analysis of a number of experimental data. Important differences between a liquid-like state and a glass-like (amorphous) state are also considered.     

Spectroscopic investigation of propargyl aryl ethers

Conclusions The UV, Raman, and IR spectra of propargyl ethers are evidence of the absence of interaction between the CC group and the oxygen atom through the methylene bridge.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 84–87, January, 1974.     

Towards a Renormalized Lattice Boltzmann Equation for Fluid Turbulence

A coarse-grained Lattice Boltzmann equation is examined in which the effects of unresolved (subgrid) scales are formally incorporated within a renormalized relaxation time of the collision operator. Actual values of the renormalized relaxation time are analyzed for the practical case of high-Reynolds flows past slant bodies (airfoils).     

Mechanism of the ring-chain tautomerism of 2,3,3-trimethyl-2-hydroxy-5-pyrrolidones

The mechanism of the prototropic equilibrium process of ring-chain tautomerization of 2,3,3-trimethyl-2-hydroxy-5-pyrrolidones is discussed on the basis of the results obtained by PMR spectroscopy. On the NMR time scale the reaction proceeds with the formation of a common intermediate anion, and the rate-determining step is the detachment of a proton.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 616–619, May, 1979.     

Study of the formation of 2-substituted 3a,4,6,6a-tetrahydrothieno[3,4-d]oxazolines from cis- and trans-4-amino-3-hydroxythiophans

The formation of 2-substituted 3a,4,6,6a-tetrahydrothieno[3,4-d]oxazolines from N-acyl-substituted cis-and trans-4-amino-3-hydroxythiophans in deuteroacetic acid and by the action of thionyl chloride was studied. Only the derivatives of cis-4-amino-3-hydroxythiophans are cyclized in deuteroacetic acid. The formation of an oxazoline ring from 4-amino-3-hydroxythiophan by the action of thionyl chloride depends both on the relative position of the hydroxy and amino groups and on the character of the acyl substituent attached to the amino group.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 913–917, July, 1974.