Synthesis of <Emphasis Type="Italic">N</Emphasis>-(2-aminoethyl)- and <Emphasis Type="Italic">N</Emphasis>-(3-aminopropyl)cytisine

2-(N-cytisinyl)acetamide or 3-(N-cytisinyl)propanamide were prepared by treatment of the methyl esters of N-cytisinylacetic or 3-(N-cytisinyl)propanoic acids with aqueous NH₄OH. N-(2-Aminoethyl)-or N-(3-aminopropyl)cytisine was synthesized by reduction of the amide with (i-Bu)₂AlH.     

Synthesis of (<Emphasis Type="Italic">E</Emphasis>)-<Emphasis Type="Italic">N</Emphasis>-(3-alkoxy-4-acyloxyphenylmethylene)-<Emphasis Type="Italic">N</Emphasis>-(<Emphasis Type="Italic">e</Emphasis>-cyclohexyl)amines

Previously unknown E isomers of azomethines (Schiff bases) were synthesized from vanillal and vanillin esters by their reaction with cyclohexylamine.     

Conformations and properties of <Emphasis Type="Italic">O</Emphasis>-Alkyl-<Emphasis Type="Italic">S</Emphasis>-(2-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dialkylamino)-ethylmethylthiophosphonates

Conformers of the biologically active compounds CH₃P(O)(OR)(SCH₂CH₂NR ₂ ^′ ), where (I) R = i-C₄H₉, R′ = C₂H₅ and (II) R = C₂H₅, R′ = i-C₃H₇, are calculated within the AM1 level of theory. The elongated and twisted forms with maximum and minimum distances between a nitrogen atom and those of a phosphorus tetrahedron, respectively, and bearing a syn and anti oriented alkoxy group relative to a phosphoryl oxygen, are studied. It is found that the differences between the energy, electronic, and geometric parameters of these forms are apparent in differences between their properties, e.g., the ability to participate in complexation and protonation, reactions that to some extent simulate the interaction between a substance and a biological object.     

Thiocyanation of <Emphasis Type="Italic">N</Emphasis>-arylsulfonyl-, <Emphasis Type="Italic">N</Emphasis>-aroyl-, and <Emphasis Type="Italic">N</Emphasis>-[(<Emphasis Type="Italic">N</Emphasis>-arylsulfonyl)benzimidoyl]-1,4-benzoquinone imines

Reactions of thiocyanate ion with N-aroyl-, N-arylsulfonyl-, and N-(N-arylsulfonylbenzimidoyl)-1,4-benzoquinone imines follow the 1,4-addition pattern, and the adducts undergo intramolecular cyclization to give the corresponding N-substituted 5-amino-1,3-benzoxathiol-2-ones as final products.     

Molecular structure of <Emphasis Type="Italic">N</Emphasis>-(<Emphasis Type="Italic">o</Emphasis>-and <Emphasis Type="Italic">p</Emphasis>-hydroxybenzyl)cytisine

The molecular structures of N-(o-and p-hydroxybenzyl)cytisine were investigated by NMR spectroscopy, x-ray structure analysis, and molecular modeling. It was found that NMR resonances of the OH and aromatic protons in N-(o-hydroxybenzyl)cytisine were doubled because of the presence of two conformers in solution. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 165–168, March–April, 2008.     

Copolymer of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-diallyl-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylammonium chloride with maleic acid as drug carrier

A copolymer of N,N-diallyl-N,N-dimethylammonium chloride with maleic acid of constant composition was prepared under the conditions of radical initiation. The possibility of the functionalization of the copolymer with drugs containing amino groups by polymer-analogous transformations was examined. Conditions were found for preparing conjugates of the copolymer with isoniazid. The structures and the quantitative compositions of the conjugates were determined by ¹³С NMR spectroscopy, and the possibility of preparing conjugates with controlled drug content was demonstrated.     

Molecular properties of the copolymers of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-diallyl-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylammonium chloride and maleic acid

The hydrodynamic and conformational properties of molecules of poly(N,N-diallyl-N,N-dimethylammonium chloride) and N,N-diallyl-N,N-dimethylammonium chloride-maleic acid copolymers of different compositions in solutions with various ionic-strength and pH values, as well as of the polyelectrolyte complex based on the copolymer with dodecyl sulfate anions in chloroform, are studied. For poly(N,N-diallyl-N,N-dimethylammonium chloride) molecules in a 1 M NaCl solution, the Kuhn segment length and the hydrodynamic diameter of the chain are estimated as A = 3.9 nm and d = 0.48 nm, respectively. In acidic solutions with pH 3.5, the copolymers demonstrate behavior typical for polyelectrolytes. In an alkaline solution with pH 13, when 1 M NaCl is added to the solution of the copolymer containing 29 mol % maleic acid units, there is an antipolyelectrolyte effect that manifests itself as an increase in the intrinsic viscosity of the copolymer and in the hydrodynamic radius of its molecules. It is found that an increase in the fraction of maleic acid units in the copolymer from 12 to 42 mol % brings about a reduction in the equilibrium rigidity of its macromolecules from 4.1 to 2.2 nm. The equilibrium rigidity of polyelectrolyte-complex molecules is higher than that of initial copolymer molecules owing to steric interactions arising between the aliphatic chains of dodecyl sulfate anions. In an electric field, the molecules of the complex are oriented owing to the induced dipole moment resulting from the displacement of dodecyl sulfate anions along the chain contour.     

Reactions of <Emphasis Type="Italic">N</Emphasis>-acetyl- and <Emphasis Type="Italic">N</Emphasis>-ethoxycarbonyl-2-(1-cycloalken-1-yl)anilines with <Emphasis Type="Italic">meta</Emphasis>-cloroperbenzoic acid

Reaction of N-ethoxycarbonyl-2-(1-cycloalken-1-yl)anilines with meta-cloroperbenzoic acid leads to the corresponding 2-[1-o-(3-chlorobenzoyl)-2-hydroxycyclopent-1-yl]anilines. 5-(2-Acetylaminophenyl)-5-oxopentanic or 6-oxohexanic acids are formed as main products in the reaction of N-acetyl-2-(1-cycloalken-1-yl)anilines with m-chloroperbenzoic acid in CH₂Cl₂. N-Acetyl-2-(1-cyclopenten-1-yl)-3,6-dimethylaniline is an exception in this series since its reaction stops at the stage of epoxide formation.     

3-(4-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylaminophenyl)-2-nitro-1-phenylprop-2-en-1-one by <Superscript>13</Superscript>C NMR spectroscopy and X-ray diffraction analysis

X-ray diffraction analysis established that 3-(4-N,N-dimethylaminophenyl)-2-nitro-1-phenylprop-2-en-1-one has E configuration both in crystal and in solution. The benzoyl group deviates from the styrene plane by 89.83°. The elongation of the C=C bond and shortening of its surrounding single bonds points to a high polarization of the molecule, implying a great contribution of the bipolar structure to the ground state.     

Reactions of 1-nitrocyclohexene with <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-binucleophiles

A modification of 1-nitrocyclohexene synthesis is proposed; its reaction with phenylhydrazine and benzoic acid hydrazide is shown to afford monoadducts, and with hydrazine hydrate, bisaduct. With diphenylguanidine occurs heterocyclization to 1-phenyl-2-N-phenylamino-4,5,6,7-tetrahydrobenzimidazole, whose structure is confirmed by the X-ray diffraction data. The analysis performed for this compound of the electron density distribution function in the crystal made it possible to estimate the charge distribution, π-electrons delocalization nature, and the role of N-H…N, C-H…H-C and C-H…C interactions in the formation of the crystal packing.     

Synthesis and structure of <Emphasis Type="Italic">N</Emphasis>-(diaminomethylidene)- and <Emphasis Type="Italic">N</Emphasis>-[bis(cyclohexylamino)methylidene]trifluoromethanesulfonamides

N-Trifluoromethylsulfonyl-substituted guanidines CF₃SO₂N=C(NHR)₂ (R = H, cyclohexyl) were synthesized in nearly quantitative yield by reactions of N-sulfinyltrifluoromethanesulfonamide CF₃SO₂N=S=O with urea and of trifluoromethanesulfonamide with N,N′-dicyclohexylcarbodiimide. N-[Bis(cyclohexylamino)-methylidene]trifluoromethanesulfonamide was subjected to protonation with trifluoromethanesulfonic acid and bis(trifluoromethanesulfonyl)imide, and the structure of the resulting salts and initial N-trifluoromethylsulfonylguanidines was studied by NMR and IR spectroscopy and DFT quantum-chemical calculations.     

Reactions of <Emphasis Type="Italic">N</Emphasis>-(2,2,2-trichloroethylidene)- and <Emphasis Type="Italic">N</Emphasis>-(2,2-dichloro-2-phenylethylidene)arenesulfonamides with biuret

N-(2,2,2-Trichloroethylidene)- and N-(2,2-dichloro-2-phenylethylidene)arenesulfonamides react with an equimolar amount of biuret to give 1-(1-arylsulfonylamino-2,2,2-trichloroethyl)- or 1-(1-arylsulfonylamino-2,2-dichloro-2-phenylethyl)biurets. The reactions with 2 equiv of N-(polychloroethylidene)arenesulfonamides involve both amino groups in the biuret molecule, yielding the corresponding 1,5-bis(1-arylsulfonylamino-2,2,2-trichloroethyl)- and 1,5-bis(1-arylsulfonylamino-2,2-dichloro-2-phenylethyl)biurets.     

Cyclization of trifluoro-<Emphasis Type="Italic">N</Emphasis>-(prop-2-yn-1-yl)methanesulfonamides to <Emphasis Type="Italic">N</Emphasis>-(hydroxymethyl)-1,2,3-triazoles

Three-component heterocyclizations of trifluoro-N-(prop-2-yn-1-yl)methanesulfonamide, trifluoro-N-pheny-N-(prop-2-yn-1-yl)methanesulfonamide, and trifluoro-N,N-di(prop-2-yn-1-yl)methanesulfonamide with formaldehyde and sodium azide afforded N-{[2-(hydroxymethyl)-2H-1,2,3-triazol-4-yl]methyl}-, N-{[2-(hydroxymethyl)-2H-1,2,3-triazol-4-yl]methyl}-N-phenyl-, and N,N-bis{[2-(hydroxymethyl)-2H-1,2,3-triazol-4-yl]methyl}trifluoromethanesulfonamides as the major products together with minor 1-(hydroxymethyl)-1H-1,2,3-triazole isomers.     

A new group of potential antituberculotics: <Emphasis Type="Italic">N</Emphasis>-(2-pyridylmethyl)salicylamides and <Emphasis Type="Italic">N</Emphasis>-(3-pyridylmethyl)salicylamides

As a part of our systematic study of antimycobacterially active derivatives of salicylamides, a series of nineteen derivatives of N-(2-pyridylmethyl)salicylamides and N-(3-pyridylmethyl)salicylamides was synthesised. The compounds exhibited in vitro activity against Mycobacterium tuberculosis and M. avium. Their lipophilicity, R _M, was measured by thin layer chromatography on silica gel impregnated with trioctadecylsilane and the logarithm of the partition coefficient (octanol-water), logP, was calculated. Both the parameters of lipophilicity correlated. The quantitative relationship between the structure and antimycobacterial activity was calculated. Antimycobacterial activity increased with an increase in lipophilicity. The N-(2-pyridylmethyl)salicylamide derivatives were more active than the derivatives of isomeric N-(3-pyridylmethyl)salicylamides. The geometry of compounds was calculated and the calculation was verified by measuring the length of the hydrogen bond between hydroxyl and carbonyl groups on the salicylic moiety.     

Synthesis of <Emphasis Type="Italic">N</Emphasis>-(2,2-Dichlorovinyl)arenesulfonamides by Dehydrochlorination of <Emphasis Type="Italic">N</Emphasis>-(2,2,2-Trichloroethyl)arenesulfonamides

Preparation method was developed for N-(2,2-dichlorovinyl)-N-alkylarenesulfonamides based on dehydrochlorination of the corresponding N-(2,2,2-trichloroethyl)-N-alkylarenesulfonamides.     

Solution Thermodynamics of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis><Superscript>/</Superscript>-Ethylenebis-(salicylideneiminato)-diaquochromium(III) Chloride in Aqueous Dimethylsulphoxide

The densities, viscosities and refractive indices of N,N ^/-ethylene-bis(salicylideneiminato)-diaquochromium(III) chloride, [Cr(salen)(H₂O)₂]Cl, in aqueous dimethylsulfoxide (DMSO) with different mass fractions (w ₂ = 0.20, 0.40, 0.60, 0.80 and 1.00) of DMSO were determined at 298.15, 308.15 and 318.15 K under atmospheric pressure. From measured densities, viscosities and refractive indices the apparent molar volumes (V _φ ), standard partial molar volume (V _φ ⁰ ), the slope (S _V ^* ), standard isobaric partial molar expansibility (φ _E ⁰ ) and its temperature dependence (?φ _E ⁰ /?T) _p , the viscosity B-coefficient, its temperature dependence (?B/?T), solvation number (S _n ) and apparent molar refractivity (R _D ^φ ), etc., were calculated and discussed on the basis of ion–ion and ion–solvent interactions. These results revealed that the solutions are characterized by ion–solvent interactions rather than by ion–ion interactions and the complex behaves as a long range structure maker. Thermodynamics of viscous flow was discussed in terms of transition state theory.     

Conformational isomerization of <Emphasis Type="Italic">N</Emphasis>-(naphthalen-1-yl)-<Emphasis Type="Italic">N</Emphasis>-(phenyl(quinolin-3-yl)methyl)amide derivatives

A series of N-(naphthalen-1-yl)-N-(phenyl(quinolin-3-yl)methyl)amide derivatives were designed and synthesized as anti-Mycobacterium tuberculosis drugs. NMR spectra showed that two conformational isomers of these compounds exist in solution, which is not due to cis-trans isomerization of amide bond. We proposed that the spatial interactions between three large aromatic groups caused the conformational isomerization, which was supported by molecular modeling and X-ray diffraction.