


Том 54, № 8 (2018)
- Год: 2018
- Статей: 27
- URL: https://bakhtiniada.ru/1070-4280/issue/view/13554
Article
Anthracene-Containing Podands, Ion-Active Molecular Switches of Fluorescence Characteristics
Аннотация
2,2′-[Ethane-1,2-diylbis(oxy)]bis[N-(anthracen-9-ylmethyl)ethanamine] and its bisphenylthiourea and bisthiourea derivatives have been synthesized. The diamine, being a certain analog of an aza-crown ether with an open chain, exhibits a 50 times increase in the relative fluorescence intensity (off-on process) in the presence of cadmium(II) cations. Bis(phenylthiourea) is a bifunctional fluorophore sensitive to mercury(II) cations (emission flaring) and fluoride anions (emission quenching). Anions F–, CN–, H2PO4–, and AcO– lead to a practically complete quenching of the fluorescent properties of the bis(thiourea) (off-on process).



Hydroxylamine Reactions with Peroxide Products of Alkenes Ozonolysis
Аннотация
Reactions were studied of peroxide ozonolysis products obtained from linear and cyclic alkenes with hydroxylamine prepared in situ from NH2OH·HCl by hydrogen chloride neutralization with sodium acetate. A one-pot reactions sequence was performed: alkene oxidation with ozone → reduction to a carbonyl compound with hydroxylamine → condensation of the carbonyl compound with hydroxylamine providing a possibility of direct transformation of alkenes in keto- and aldoximes excluding the stage of preparation and isolation of the carbonyl compound.



Synthesis of N-(Adamantan-1-yl)carbamides by Ritter Reaction from Adamantan-1-ol and Nitriles in the Presence of Cu-Catalysts
Аннотация
A selective synthesis of (Z)-N-(adamantan-1-yl)carbamides by the reaction of adamantan-1-ol and nitriles in the presence of Cu catalysts was carried out. Z-Conformation of amides is established basing on X-ray diffraction analysis and 2D NMR data.



Structure and Rearrangements of 7-(Heptaphenylcycloheptatrienyl)isochalcogencyanates
Аннотация
According to DFT B3LYP/6-31G(d,p) calculations, the intramolecular migration of NCX groups (X = O, S, Se, Te) in 7-(heptaphenylcycloheptatrienyl)isochalcogencyanates in the gas phase proceeds via the dissociation–recombination mechanism. Structures were found of transition states preceding the formation of tight ion pairs. High activation barriers to the migration of isochalcogencyanate groups (\(\Delta E{^\neq_{\rm{ZPE}}}\) 26.7, 21.3, 20.5, 19.3 kcal mol–1) originate from the existence of stable conformation of molecules with NCX groups located in the equatorial position and are in agreement with the data of dynamic NMR. For the transition of the molecule in the form favorable for the NCX group migration an inversion of the seven-membered ring and the rotation of the phenyl group are necessary.



Synthesis of Benzyl Alkyl Ethers by Intermolecular Dehydration of Benzyl Alcohol with Aliphatic Alcohols under the Effect of Copper Containing Catalysts
Аннотация
Synthesis of benzyl alkyl ethers was performed in high yields by intermolecular dehydration of benzyl and primary, secondary, tertiary alcohols under the effect of copper containing catalysts. The formation of benzyl alkyl ethers occurs with participation of benzyl cation.



Synthesis of Potentially Bioactive 6-Bromobenzo[f]isoindolinium Bromides by Base-Catalyzed Intramolecular [4+2]-Cycloaddition
Аннотация
Intramolecular cyclization of bromides of diethyl-, dipropyl-, and penthamethylenepropargyl[3-(4-bromophenyl)prop-2-ynyl]ammonium into 6-bromobenzo[f]isoindolinium bromides catalyzed with bases occurs with moderate self-heating. The morpholine analog even in more diluted solutions reacts with vigorous self-heating. Cyclization of dimethyl analog takes place only at heating at 80–85°C during 1 h.



Three-Component Synthesis and Optical Properties of Nicotinic Acid Esters Containing Buta-1,3-dien-1,1,3-tricarbonitrile Fragment
Аннотация
Three-component synthesis of ethyl 4-aryl-2-methyl-5-cyano-6-(dicyanomethylidene)-1,6-dihydropyridine-3-carboxylates was developed consisting in the reaction of acetoacetic ester, aromatic aldehydes, and malononitrile dimer in the presence of sodium nitrite. Optical properties of synthesized compounds were investigated and it was demonstrated that they possessed intensive fluorescence in solution and in solid state with emission maxima in the yellow and green region of the visible light.



One-Pot Oxidative Synthesis of Substituted Quinolines from Alcohols and Arylamines Catalyzed by Fe(CrO2)2 in Water Medium
Аннотация
One-pot tandem synthesis was developed for substituted quinolines (in up to 97% yields) involving a selective catalytic oxidation of primary amines to aldehydes and their condensation with arylamines under the action of a dispersion of Fe(CrO2)2 and water solution of H2O2 at room temperature. The stage of catalytic oxidation of alcohols was accelerated by photoactivation. A presumable mechanism of the photoactivated tandem synthesis of 2-methylquinoline was suggested. Catalyst Fe(CrO2)2 was prepared by photochemical synthesis.



Synthesis of Fused 2Н-Pyridin-2-ones under the Conditions of Multicomponent Hantzsch Reaction
Аннотация
One-pot process was studied between a substituted 4-hydroxy-2Н-pyran-2-one and aromatic aldehydes and ammonium acetate in the conditions of modified Hantzsch reaction in acid environment under thermal and microwave activation. Arylmethylenebis-4-hydroxy-2Н-pyridin-2-ones, hydrochromenopyridinone, and their oxygen-containing heteroanalogs were isolated. A primary condensation was confirmed into bispyran-2-one adducts, and at the use of salicilaldehyde, into pyranochromene with subsequent recyclization of pyranone fragments in pyridinone ones.






Mass Spectra of New Heterocycles. XVII. Main Fragmentation Routes of Molecular Ions of 4-Alkoxy-5-amino-3-methylthiophene-2-carbonitriles under Electron and Chemical Ionization
Аннотация
For the first time decomposition was investigated of 4-alkoxy-5-amino-3-methylthiophene-2-carbonitriles under the conditions of electronic (70 eV) and chemical (reagent gas methane) ionization. At the electronic ionization the compounds under study [except for 4-(1-ethoxyethoxy) and 4-(ferrocenylmethoxy) derivatives] form stable molecular ions that decompose mainly by the cleavage of an alkyl radical from the alkoxy-substituent. Further fragmentation of the arising ion [M–Alk]+ depends on the substituent nature in the amino group. In the mass spectrum of 4-(ferrocenylmethoxy)-substituted thiophene peaks of the ion [FcCH2]+ and its fragmentation products prevail. In the mass spectra of chemical ionization predominant peaks belong to ions M+·, [M + H]+ and [M + C2H5]+, and fragment ions are absent.



Thermal Rearrangements of 3H- and 4H-Pyrazoles Prepared by Reactions of 9-Diazofluoren with Methyl Tetrolate and Methyl 3-Phenylpropiolate
Аннотация
9-Diazofluoren adds in Et2O at 20°C to methyltetrolate in keeping with Auwers rule and nonregioselectively adds to methyl-3-phenylpropiolate with the formation of spirocyclic 3H-pyrazoles. The methyltetrolate adduct at boiling in toluene converts into methyl 3a-methyl-3aH-dibenzo[e,g]indazole-3-carboxylate, at 190°C in benzene, into methyl 3-methyl-2H-dibenzo[e,g]indazole-2-carboxylate, and at 160°C in methanol, into 3-methyl-2H-dibenzo[e,g]indazole. Auwers adduct of methyl 3-phenylpropiolate at boiling in benzene gives cyclopropene derivative and at boiling in methanol isomerizes into methyl 3a-phenyl-3aHdibenzo[e,g]indazole-3-carboxylate. Anti-Auwers adduct at boiling in benzene isomerizes into methyl 2-phenylpyrazolo[1,5-f]phenanthridine-3-carboxylate.



Synthesis and Reactivity of Fusion Product of 2-Methylthiazole Fragment to 2-(Furan-2-yl)benzimidazole
Аннотация
Reaction of 1,2-diamino-4-nitrobenzene with furan-2-carbaldehyde in the presence of copper sulfate afforded 2-(furan-2-yl)-5(6)-nitro-1H-benzimidazole. Its N-methylation provided 1-methyl-5(6)-nitro isomers. After reduction of isomers with tin in conc. HCl a pure 3-methyl-2-(furan-2-yl)benzimidazol-5-amine was obtained. The condensation of this amine with acetic anhydride led to the formation of N-[3-methyl-2-(furan-2-yl)benzimidazol-5-yl]acetamide whose treatment with excess P2S5 in anhydrous pyridine resulted in the corresponding thioamide. The latter was oxidized with K3[Fe(CN)6] in alkaline environment to obtain 2,8-dimethyl-7-(furan-2-yl)-8H-imidazo[4,5-g][1,3]benzothiazole. Its reactions of electrophilic substitution were studied: nitration, bromination, sulfonation, formylation, acylation. The substituent is introduced exclusively in the position 5 of the furan ring.



Nitration of 3-Methylaceperidazines with a Large Excess of Fuming Nitric Acid
Аннотация
Nitration of N-acetyl-3-methylaceperidazine with a 2–3-fold excess of nitric acid (d 1.36, 1.48) in glacial acetic acid results in the exclusive formation of mono- and dinitroderivatives. The nitration of 3-methylaceperidazine and its N-alkyl- and N-acetyl-substituted derivatives with a 6–9-fold excess of fuming nitric acid (d 1.54) in the same conditions results in the formation of both the expected products of mono- and dinitration and a product of the electrophilic addition of nitric acid to a double bond of acenaphthene scaffold of the molecule of nitration product.



Formation of N–S Bonds in Reactions of 2-[2-Oxo-1-(tosyloxyimino)-2-phenylethyl]pyrimidin-4(3H)-one and Its 6-derivatives with Thiourea and Potassium Thiocyanate
Аннотация
Reaction of potassium thiocyanate with 2-[2-oxo-1-(1-tosyloxyimino)-2-phenylethyl]pyrimidin-4-(3H)-one derivatives led to the formation of a new fused heterocyclic system with a common nitrogen atom, substituted 7H-[1,2,5]thiadiazolo[2,3-a]pyrimidin-7-one.






New Reactions of (2-Aminophenyl)diphenylmethanol with Carbonyl Compounds
Аннотация
Reactions of (2-aminophenyl)diphenylmethanol with ketones (dimedone, camphor, and 3-bromocamphor) in acetic acid result in the formation of arylimines of camphore and 3-bromocamphore, substituted tetrahydroacridin-1(2H)-one and 2-methyl-4,4-diphenylbenzoxazine.



Alkylation of 2-Sulfanylbenzoxazole with α-Iodoketones in the Absence of Bases
Аннотация
Reaction of 2-sulfanylbenzoxazole with 1-iodopropan-2-one, 2-iodo-1-phenylethanone, and 2-iodo-1-(thiophen-2-yl)ethanone without solvent and bases afforded bis(benzoxazol-2-yl)disulfonium derivatives in a single preparative stage. The reaction proceeds as a domino-process and includes the alkylation of a sulfanyl group of benzoxazole, the reduction of iodoketone with hydrogen iodide, the oxidation of 2-sulfanylbenzoxazole to disulfide, the alkylation of disulfide atoms of sulfur, and the formation of triiodideanions. The yield of disulfonium derivatives increases twice in the presence of equimolar amount of iodine.



Synthesis of 2-[3-Aryl-3-(5-phenylisoxazol-3-yl)propyl] Derivatives of 5,5-Dimethylcyclohexane- and Cyclopenthane-1,3-diones Proceeding from 2-(4-Nitro-3-arylbutyl) Precursors
Аннотация
Regiospecific reduction of carbonyl group of acyl chain in the previously described 4-nitro-3-arylbutanoyl derivatives of dimedone and cyclopentane-1,3-dione was performed. On the basis of nitromethyl group of the enol derivatives of the reduction products obtained from the mentioned compounds nitrile oxide intermediates were prepared, which in situ reacted with phenylacetylene to form the corresponding isoxazole derivatives.



Synthesis and Chemical Transformations of 5-Alkyl(phenyl)-4,5,6,7-tetrahydro[1,2,4]triazolo[1,5-a]pyrimidin-7-oles
Аннотация
5,5,7-Trimethyl-4,5,6,7-tetrahydro[1,2,4]triazolo[1,5-a]pyrimidin-7-ol was synthesized by cyclocondensation of 3-amino-1,2,4-triazole with 4-methylpent-3-en-2-one; its chemical transformations, and also the transformations of 5-phenyl-4,5,6,7-tetrahydro[1,2,4]triazolo[1,5-a]pyrimidin-7-ol were investigated in reactions with reagents of diverse electronic nature.



One-Pot Synthesis of 3,5-Disubstituted 1,2,4-Oxadiazoles Using Catalytic System NaOH‒DMSO
Аннотация
One-pot convenient process was developed for the production of 3,5-disubstituted 1,2,4-oxadiazoles by reaction of amidoximes with anhydrides or acyl chlorides in a system NaOH‒DMSO. The reaction proceeds at room temperature with high yields.



Short Communications
Three-Component Stereoselective Synthesis of (1R,2S)-1-Aryl-2-{[prop-2-yn(en)yloxy]methyl}spiro[2,4]hepta-4,7-diones
Аннотация
Three-component reaction involving cyclopentane-1,3-dione, substituted benzaldehydes, and chloromethyl propyn(en)yl ethers results in a stereoselective formation of trans-1-aryl-2-{[prop-2-(yn)enyloxy]-methyl}spiro[2,4]hepta-4,7-diones in satisfactory yields.






Regioselective Reaction of Pyridine-2-Sulfenyl Chloride with Isoeugenol
Аннотация
Proceeding from 2,2′-disulfanediyldipyridine and isoeugenol a regioselective one-pot synthesis was developed affording 3-(4-hydroxy-3-methoxyphenyl)-2-methyl-2H,3H-[1,3]thiazolo[3,2-a]pyridin-4-ium chloride in a 70% yield.











