Unusual course of reaction of triphenyl(2-<Emphasis Type="Italic">p</Emphasis>-toluylethyl)phosphonium bromide with hydrazine

The reaction of triphenyl(2-p-toluylethyl)phosphonium bromide with hydrazine hydrochloride yields, along with the hydrazone, 6-p-tolyl-2,3-dihydropyridazin-3-one as a minor product.     

Transformations of 5-chloro-2-hydrazino-4-<Emphasis Type="Italic">p</Emphasis>-tolylsulfonyl-1,3-thiazole

Accessible 2,2-dichloro-1-p-tolylsulfonylethenyl isothiocyanate reacted with hydrazine hydrate to give 5-chloro-2-hydrazino-4-p-tolylsulfonyl-1,3-thiazole whose reactions with thiols and amines followed a complicated pattern. Treatment of 5-chloro-2-hydrazino-4-p-tolylsulfonyl-1,3-thiazole with acetylacetone led to the formation of previously unknown 5-chloro-2-(3,5-dimethyl-1H-pyrazol-1-yl)-4-p-tolylsulfonyl-1,3-thiazole which reacted with O-, S-, and N-centered nucleophiles at the C⁵ atom with high regioselectivity.     

Cycloaddition and chlorotropic transformations in reactions of dichloromethylenetrifluoroacetamide with phosphites

Reactions of dichlormethylenetrifluoroacetamide with triphenyl phosphite, diethylchlorophosphite (o-phenylene)diethylamidophosphite, (o-phenylene)chlorphosphite, and 2-fluoro-3-isopropyl-5-tert-butyl-1,3,2-oxazaphospholine proceeded as cheletropic [4+1]-cycloaddition. The formed λ⁵-1,4,2-oxazaphospholines underwent 1,3-migration of the chlorine atom in C=N–C cyclic triad.     

Acyl iodides in organic synthesis. Reactions of acetyl iodide with urea,thiourea, and their <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-disubstituted derivatives

Acetyl iodide reacted with urea and its derivatives to give the corresponding N-substituted products. The reactions of acetyl iodide with thiourea, N,N′-dimethylthiourea, imidazolidine-2-thione, and hexahydropyrimidine-2-thione resulted in the formation of S- or N-acetyl derivatives, depending on the temperature and structure of the sulfur functionality (thione or thiol). By contrast, in the reaction of acetyl iodide with N,N′-bis(3-triethoxysilylpropyl)thiourea one ethoxy group on the silicon atom was replaced by iodine with formation of N-{3-[(diethoxy)iodosilyl]propyl}-N′-[3-(triethoxysilyl)propyl]thiourea. The latter decomposed on heating to give 3-triethoxysilylpropyl isothiocyanate and silicon-containing polymer with the composition C₄₅H₉₇IN₆O_14.5S₃Si₆.     

2-amino-4,5,6,7-tetrahydro-1,2,4-triazolo[1,5-<Emphasis Type="Italic">a</Emphasis>]pyrimidines: Synthesis and reactions with electrophilic reagents

The hydrogenation of 2-amino-5-R-7-R′-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidines with NaBH₄ led to the formation of 2-amino-5-R-7-R′-4,5,6,7-tetrahydro-1,2,4-triazolo[1,5-a]pyrimidines. Acylation, sulfonylation, and alkylation of these compounds depending on conditions and the reagent character occur at the amino group, atoms N³ or N⁴. The treatment with alkali of 2-amino-3-benzyl-5-R-7-R′-4,5,6,7-tetrahydro-1,2,4-triazolo-[1,5-a]pyrimidinium bromide resulted in 2-amino-3-benzyl-5-R-7-R′-3,5,6,7-tetrahydro-1,2,4-triazolo[1,5-a]-pyrimidine, similar reaction of 2-acetamido-3-benzyl-5-R-7-R′-4,5,6,7-tetrahydro-1,2,4-triazolo[1,5-a]-pyrimidinium bromide gave a mesoionic product of a hydrogen elimination from the amide nitrogen atom.     

Synthesis,S-alkylation,and fungicidal activity of 4-(benzylideneamino)thioglycolurils

A series of 1,3-disubstituted 4-benzylideneamino-5-thioxohexahydroimidazo[4,5-d]imidazol-2(1H)-ones (thioglycolurils) was synthesized via the reaction of 5,7-disubstituted 3-thioxoperhydroimidazo[4,5-e]-1,2,4-triazin-6-ones with hydroxy-, alkoxy-, and fluorocontaining benzaldehyde derivatives. An alkylation of the obtained thioglycolurils with methyl iodide or 4-bromobenzyl bromide provided the corresponding 6-benzylideneamino-5-alkylsulfanyl-3,3a,6,6a-tetrahydroimidazo[4,5-d]imidazol-2(1H)-ones. The fungicidal activity of some synthesized compounds against pathogens causing diseases of agricultural crops was studied.     

Alkylation of 4,5-dihydro-1<Emphasis Type="Italic">H</Emphasis>-imidazole-2-thiol with iodomethylsilanes and -siloxanes

The alkylation of 4,5-dihydro-1H-imidazole-2-thiol with 1-iodomethyl(dimethyl)phenylsilane, 1-(iodomethyl)-1,1,3,3,3-pentamethyldisiloxane, and 1,3-bis(iodomethyl)-1,1,3,3-tetramethyldisiloxane involved iodine-catalyzed cleavage of the Si–C_sp ² and Si–O bonds with liberated (in situ) hydrogen iodide to afford 2-({[(4,5-dihydro-1H-imidazolium-2-ylsulfanyl)methyl]-1,1,3,3-tetramethyldisiloxanylmethyl}sulfanyl)-4,5-dihydro-1H-imidazolium di- and tetraiodides. Replacement of iodide ion in the products by triiodide gives new organosilicon ionic liquids with several charged fragments.     

Selective monoallylation of β-cyclodextrin

Reaction of β-cyclodextrin with allyl bromide in dimethyl sulfoxide affords 2-О-allyl-β-cyclodextrin, while in dimethylformamide 6-О-allyl-β-cyclodextrin is formed. Optimal conditions of the reaction were found allowing to obtain the target products in quantitative yield.     

Reaction of <Emphasis Type="Italic">N</Emphasis>-phenyltriflamide with 1,2-dibromoethane and propargyl bromide. Unexpected cleavage of С–С and С–N bonds

Reaction of N-phenyltriflamide with 1,2-dibromoethane under basic conditions in DMSO unexpectedly results in N-methyl-N-phenyltriflamide and 1,3-diphenylurea. The presumed reaction mechanism includes the formation of unstable intermediate disubstitution product TfN(Ph)CH₂CH2N(Ph)Tf that suffers the the С–С bond cleavage resulting in TfN(Me)Ph and N,N′-methanediylbis(N-phenyltriflamide). The latter reacts with K₂CO₃ releasing two molecules of potassium triflinate and after hydrolysis of diphenylcarbodiimide PhN=C=NPh gives 1,3-diphenylurea. With propargyl bromide, N-phenyltriflamide affords N-propargyl-Nphenyltriflamide in high yield. The bromination of the latter results in a mixture of Z,E-isomers of N-(2,3-dibromoprop-2-en-1-yl)-N-phenyltriflamide which undergo dehydrobromination giving first N-(3-bromopropanedienyl)-N-phenyltriflamide and then the products of the C–N bond cleavage: N-phenyltriflamide and 3,3-dimethoxyprop-1-yne.     

Synthesis of 5,8-Diamino-Substituted Pyrano[4″,3″:4′,5′]pyrido[3′,2′:4,5]thieno[3,2-<Emphasis Type="Italic">d</Emphasis>]pyrimidines and Pyrimido[4′,5′:4,5]thieno[2,3-<Emphasis Type="Italic">c</Emphasis>]isoquinolines

Ethyl 1-amino-8,8-dimethyl-5-(piperidin-1-yl)-8,9-dihydro-6H-pyrano[4,3-d]thieno[2,3-b]pyridine-2-carboxylate and ethyl 1-amino-5-(piperidin-1-yl)-6,7,8,9-tetrahydrothieno[2,3-c]isoquinoline-2-carboxylate reacted with benzoyl isothiocyanate to give the corresponding 1-thioureido derivatives which underwent cyclization to 2,2-dimethyl-5-(piperidin-1-yl)-10-thioxo-1,4,10,11-tetrahydro-2H-pyrano[4″,3″:4′,5′]pyrido-[3′,2′:4,5]thieno[3,2-d]pyrimidin-8(9H)-one and 5-(piperidin-1-yl)-10-thioxo-1,2,3,4,10,11-hexahydropyrimido-[4′,5′:4,5]thieno[2,3-c]isoquinolin-8(9H)-one. The cyclization products were converted into 8-chloro derivatives, and the chlorine atom therein was replaced by various amines.     

Electron density distribution in crystals of the antimony(V) spiroendoperoxide complexes

The experimental and theoretical electron densities in complexes [6-(2,6-di-iso-propylphenyl)imino-2,4-di-tert-butylcyclohexa-2,4-diene-1-peroxo-1-olato-N,O,O′]tris(p-chlorophenyl)antimony(V), (p-Cl–C₆H₄)₃Sb(2,6-iso-Pr–Ph–AP) · O₂ (I), and [6-(2,6-dimethylphenyl)imino-2,4-di-tert-butylcyclohexa-2,4-diene-1-peroxo-1-olato-N,O,O′]tris(p-chlorophenyl)antimony(V), (p-Cl–C₆H₄)₃Sb(2,6-Me–Ph–AP) · O₂ (II), where AP is 4,6-di-tert-butyl-N-o-iminobenzoquinone dianion, are studied on the basis of high-resolution X-ray diffraction data and theoretical calculations using the density functional theory (B3LYP/DGDZVP). The nature of chemical bonds and the charge distribution on atoms are studied, and the energy of molecular oxygen addition to the Sb(V) o-aminophenolate complexes is estimated. The structures are deposited with the Cambridge Crystallographic Data Centre (CIF files CCDC nos. 1560600 (spherical refinement) and 1560601 (multipole refinement) for complex I; 1560602 (spherical) and 1560603 (multipole) for complex II).     

Nitration of 1,3-dihydro-2<Emphasis Type="Italic">H</Emphasis>-imidazo[4,5-<Emphasis Type="Italic">b</Emphasis>]pyridin-2-one derivatives

Nitration of 1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one and its N-methyl derivatives at 0–5°C and 60°C gives 5-nitro-and 5,6-dinitro-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-ones, respectively. The latter can also be obtained by nitration of 5-mononitro derivatives under similar conditions. The nitration of 6-chloro-and 6-bromo-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-ones and their N-methyl-substituted analogs leads to the formation of the corresponding 6-chloro(bromo)-5-nitro compounds. The same products are formed in the nitration of 5,6-dichloro-and 5,6-dibromo-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-ones. In this case, the process involves replacement of the halogen atom in position 5 of the pyridine fragment by nitro group. The nitration of 6-bromo-5-methyl-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one is accompanied by oxidation of the 5-methyl group to carboxy.     

Chemoselective acylation of monosubstituted thiacalix[4]arene with di-<Emphasis Type="Italic">tert</Emphasis>-butyl dicarbonate

Mono-, di-, and tetrasubstituted derivatives of p-tert-butylthiacalix[4]arene containing tert-butylcarbamate, tert-butylcarbonate, and tert-butyl fragments have been prepared for the first time. Depending on the reaction conditions (reagents ratio, temperature, and the presence of a base), the interaction of the monoamine derivative of p-tert-butylthiacalix[4]arene with di-tert-butyl dicarbonate can lead to the formation of mono-, di-, and tetrasubstituted products.     

Homo and hetero glaser coupling involving acetylene derivatives of trifluoromethanesulfonamide

Glaser homocoupling of N,N-bispropargyltriflamide led to the formation of N,N'-hexa-2,4-diyne-1,6-diylbis(N-prop-2-yne-1-triflamide). Further condensation into a 14-membered heterocycle, 1,8-bis-(triflyl)-1,8-diazacyclotetradeca-3,5,10,12-tetrayne did not occur evidently because of rigid steric requirements to the cyclization. In the Glaser heterocoupling of N-propargyltriflamide with arylacetylenes ArC≡CH (Ar = Ph, p-CNC₆H₄) the condensation products formed in 20–30% yields.     

Synthesis of urethane—acrylic multi-block copolymers via electrochemically mediated ATRP

The electrochemically mediated atom transfer radical polymerisation (eATRP) of n-butyl acrylate was investigated under a variety of catalyst concentrations. Poly(n-butyl acrylate)-block-polyurethane-block-poly(n-butyl acrylate) copolymers were prepared via electrochemically mediated atom transfer radical polymerisation (eATRP) using only 7 × 10^?6 mole % of Cu^II complex. The successful chain extension and formation of penta-block copolymers confirmed the living nature of the poly(alkyl acrylates) prepared by eATRP. In this work, the tri-block and penta-block urethane-acrylate copolymers were synthesised for the first time by using tertiary bromine-terminated polyurethane macro-initiators as transitional products reacting with n-butyl acrylate, and subsequently with tert-butyl acrylate in the presence of the Cu^IIBr₂/TPMA catalyst complex. The results of ¹H NMR spectral studies support the formation of tri-block poly(n-butyl acrylate)-block-polyurethane-block-poly(n-butyl acrylate) copolymers, and penta-block poly(tert-butyl acrylate)-block-poly(n-butyl acrylate)-block-polyurethane-block-poly(n-butyl acrylate)-block-poly(tert-butyl acrylate) copolymers.     

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.     

Fusion of 2-(furan-2-yl)thiazole to 1-methyl-1<Emphasis Type="Italic">H</Emphasis>-benzimidazole

Methylation of 5(6)-nitro-1H-benzimidazole with methyl iodide in the presence of potassium hydroxide and N-methylpyrrolidin-2-one gave a mixture of isomeric 1-methyl-5-nitro- and 1-methyl-6-nitro-1H-benzimidazoles which were reduced with tin in concentrated aqueous HCl on heating. The resulting amines reacted with furan-2-carbonyl chloride in N-methylpyrrolidin-2-one to give furan-2-carboxamides which were treated with excess P₂S₅ in pyridine. Oxidation of isomeric furan-2-carbothioamides with K₃[Fe(CN)₆] in alkaline medium afforded a mixture of intramolecular cyclization products, 2-(furan-2-yl)-6-methyl-6H-imidazo[4,5-g][1,3]benzothiazole and 2-(furan-2-yl)-8-methyl-8H-imidazo[4,5-g][1,3]benzothiazole which were separated by column chromatography and identified.     

Electrophilic heterocyclization of 6-alken(yn)ylsulfanyl-pyrazolo[3,4-<Emphasis Type="Italic">d</Emphasis>]pyrimidin-4(5<Emphasis Type="Italic">H</Emphasis>)-ones

6-Allylsulfanyl-1-arylpyrazolo[3,4-d]pyrimidin-4(5H)-ones react with iodine and sulfuric acid to give angular pyrazolothiazolopyrimidine derivatives. The reaction of 6-(prop-2-yn-1-ylsulfanyl)-1-(4-tolyl)-pyrazolo[3,4-d]pyrimidin-4(5H)-one with sulfuric acid gives angularly fused pyrazolo[4,3-e][1,3]thiazolo-[3,2-a]pyrimidin-4-one, whereas in the reaction with sodium methoxide linearly fused pyrazolo[3,4-d][1,3]-thiazolo[3,2-a]pyrimidin-4-one was formed. Linearly fused pyrazolo[3′,4′:4,5]pyrimido[2,1-b][1,3]thiazole derivatives were also obtained by reaction of 1-aryl-6-(3-phenylprop-2-en-1-ylsulfanyl)pyrazolo[3,4-d]pyrimidin-4(5H)-ones with sulfuric acid.     

Extraction of Cesium-137 and Americium-241 by Calix[n]arenes from Carbonate-Alkaline Media

Trends of cesium-137 and americium-241 extraction from carbonate–alkaline media with p-tert-butylcalix[n]arenes with macrocycles of different size (n = 4, 6, 8), including monofunctional derivatives with lipophilic substituents for increasing their solubility in organic media, were studied. It was demonstrated that O-n-octyl ethers of p-tert-butylcalix[6]arene appeared to be the most efficient extractants for Cs(I) cations, while it was p-tert-butylthiacalix[4]arene for and americium(III) cations.     

Five-membered 2,3-dioxo heterocycles: LI. Reaction of 3-aroyl-2,4-dihydro-1<Emphasis Type="Italic">H</Emphasis>-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones with 3-amino-5,5-dimethylcyclohex-2-en-1-ones

3-Aroyl-2,4-dihydro-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones react with N-unsubstituted and N-substituted 3-amino-5,5-dimethylcyclohex-2-en-1-ones to give 3′-aroyl-4′-hydroxy-1′-(o-hydroxy-phenyl)-6,6-dimethyl-6,7-dihydrospiro[indole-3,2′-pyrrole]-2,4,5′(1H,1′H,5H)-triones. The molecular and crystalline structure of the 1-cyclohexyl-substituted derivative was studied by X-ray analysis.