Reaction of <Emphasis Type="Italic">N</Emphasis>-sulfonyl derivatives of 1,4-benzoquinone monoimine with substituted hydrazines

Reaction direction of N-sulfonyl derivatives of 1,4-benzoquinone monoimine with substituted hydrazines depends on the redox potential of the quinone imine and on the basicity of the hydrazine. Aryl (alkyl)hydrazines of high basicity favor the reduction of quinone monoimine. In reactions with less basic aroylhydrazones N'-(4-oxocyclohexa-2,5-dienylidene)aroylhydrazides were obtained only from the alkylsubstituted in the quinoid ring N-sulfonyl derivatives possessing a lower redox potential.     

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.     

Reaction of <Emphasis Type="Italic">N</Emphasis>-arenesulfonyl-1,4-benzoquinone imines with acetylacetone

N-Arenesulfonyl-1,4-benzoquinone imines reacted with acetylacetone to afford different products, depending on the isolation procedure. Crystallization from polar protic solvents gave N-[4-hydroxy- 3-(2-hydroxy-4-oxopent-2-en-3-yl)phenyl]arenesulfonamides and 6-(2-oxopropyl)-4-(arenesulfonamido)phenyl acetates, whereas N-(3-acetyl-2,6-dimethyl-1-benzofuran-5-yl)arenesulfonamides were isolated by crystallization from nonpolar aprotic solvents.     

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.     

Reaction of <Emphasis Type="Italic">N</Emphasis>-chloro-1,4-benzoquinone imines with thiols

N-Chloro-1,4-benzoquinone imines reacted with arenethiols to give different products, depending on the conditions and initial quinone imine structure. N-(Arylsulfanyl)-1,4-benzoquinone imines were obtained as a result of nucleophilic substitution of the chlorine atom, and 1,4-benzoquinone imines containing an aryl-sulfanyl substituent in the quinoid ring were formed according to the radical mechanism. The reactions of N-chloro-1,4-benzoquinone imines with heterocyclic thiols afforded only the corresponding chlorine substitution products.     

Reaction of <Emphasis Type="Italic">N</Emphasis>-sulfonyl-1,4-benzoquinone imines with enamines

N-Sulfonyl derivatives of 1,4-benzoquinone imine reacted with enamines to give 1,4-addition products and products of their subsequent cyclization, substituted 5-aminobenzofurans and 5-aminoindoles, depending on the solvent nature, electron-withdrawing power of the substituent on the quinone imine nitrogen atom, and enamine structure. The presence of strong electron-withdrawing trifluoromethanesulfonyl group on the quinone imine nitrogen atom favors formation of 1,4-addition products and benzofuran derivatives.     

Kinetics of the reaction of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylaniline with 1-bromoalk-2-ynes

Quaternization of N,N-dimethylaniline with propargyl bromide, 1-bromobut-2-yne, and 1-bromooct-2-yne were studied. It was shown that, with the lengthening chain of the substituent at the triple bond, the quaternization rate tends to increase.     

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.     

Reaction of <Emphasis Type="Italic">N</Emphasis>-sulfonyl-1,4-benzoquinone imines with sodium azide

Depending on the conditions and the order of addition of the reactants, reactions of N-sulfonyl-1,4-benzoquinone imines with sodium azide afforded N-(3-azido-4-hydroxyphenyl)alkane(arene)sulfonamides, N-(3-azido-4-oxocyclohexa-2,5-dienylidene)alkane(arene)sulfonamides, and N-(3,5-diazido-4-hydroxyphenyl)-alkanesulfonamides. Quantum chemical calculations showed that the reactions begin with addition of azide ion to the quinone imine.     

Reaction of some <Emphasis Type="Italic">N</Emphasis>-substituted 1,4-benzoquinone imines with sodium azide

The reactions of N-(arenesulfinyl)-1,4-benzoquinone imines with sodium azide afforded the corresponding N-(arylsulfanyl)-2-azido-1,4-benzoquinone imines via 1,4-addition of azide ion and subsequent intramolecular oxidation–reduction.     

<Emphasis Type="Italic">Z</Emphasis>-and <Emphasis Type="Italic">E</Emphasis>-conformers of <Emphasis Type="Italic">N</Emphasis>-chloroacetylcytisine

N-Chloroacetylcytisine was synthesized by acylation of (–)-cytisine. Stable Z- and E-conformers with respect to rotational isomerism around the N-12–CO bond were found in PMR spectra at room temperature. The point at which PMR resonances of the Z- and E-conformers coalesced upon heating was measured. The transition barrier between the conformers was estimated.     

Synthesis of amino acid conjugates of glycyrrhizic acid using <Emphasis Type="Italic">N</Emphasis>-hydroxyphthalimide and <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>'-dicyclohexylcarbodiimide

Synthesis of amino acid conjugates of glycyrrhizic acid with the use of N-hydroxyphthalimide, N,N'-dicyclohexylcarbodiimide, and tert-butyl esters of L-amino acids (valine, isoleucine, phenylalanine, and methionine) was performed followed by deprotection with trifluoroacetic acid. The target amino acid conjugates were isolated by column chromatography on silica gel in 40–45% yield. The structure of the prepared compounds was confirmed by IR and ¹³C NMR spectroscopy.     

Reactions of <Emphasis Type="Italic">N</Emphasis>-Allyl- and <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-Diallyltrifluoromethanesulfonamides with Carboxylic Acid Amides under Oxidizing Conditions

Reactions of acetamide and benzamide with N-allyltrifluoromethanesulfonamide in the presence of t-BuOCl–NaI afforded exclusively 2,5-bis(chloromethyl)-1,4-bis(trifluoromethanesulfonyl)piperazine. Analogous reaction with N,N-diallyltrifluoromethanesulfonamide gave mixed halogenation product at only one C=C double bond of the substrate.     

Synthesis and anticancer activities of 1,4-phenylene-bis-<Emphasis Type="Italic">N</Emphasis>-acetyl- and <Emphasis Type="Italic">N</Emphasis>-phenylpyrazoline derivatives

Novel 1,4-phenylene-bis-N-acetyl- (3a–h) and bis-N-phenylpyrazoline derivatives (4a–h) were obtained by addition of hydrazine hydrate and phenylhydrazine to bis-chalcone derivatives (1a–h) in acetic acid and acetic acid/ethanol for 4 and 8 h in reflux conditions, respectively. The structures of the obtained bis-N-acetylpyrazoline and bis-N-phenylpyrazoline derivatives were characterized by nuclear magnetic resonance (NMR) and infrared (IR) spectroscopic methods and elemental analysis. Compounds 3a–h and 4a–h were investigated to evaluate their anticancer activities against C6 (rat brain tumor cells) and HeLa (human uterus carcinoma) in vitro using a dose-dependent assay from 5 to 100 μM with 5-fluorouracil (5-FU) as standard anticancer drug. Compound 3a showed higher cell-selective activity compared with 5-FU against HeLa cells. Compounds 3a–h (except 3d) were shown to have better activities than 5-FU against both cells, particularly at high concentration. Compound 4c showed higher cell-selective activity compared with 5-FU against C6 cells. Compound 3a may be particularly promising as an anticancer drug against HeLa cells.     

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.     

<Emphasis Type="Italic">N</Emphasis>-halohexamethyldisilazanes

The review is devoted to N-halohexamethyldisilazanes, perspective but scantily studied halogenating agents. Methods of preparation, physiochemical characteristics, and synthetic potential are considered. Mechanisms of a number of reactions are presented.     

Kinetics and mechanism of <Emphasis Type="Italic">N</Emphasis>-chloromethylamine decomposition in solutions

Kinetics of N-chloromethylamine decomposition in an aqueous base medium and chloroform at different temperatures is studied. The decomposition of N-chloromethylamine is found to obey a second order equation in an aqueous base medium at an equimolar ratio of the reagents and a first order equation in chloroform with excess base. The activation energy of N-chloromethylamine decomposition in the both solvents is determined. A mechanism for the reaction is proposed. N-Chloromethylamine is shown to have approximately equal stability in these solvents within the studied temperature range.