Chemistry of iminofurans: IX. Synthesis and cyclization of (2<Emphasis Type="Italic">Z</Emphasis>)-2-{(2<Emphasis Type="Italic">Z</Emphasis>)-2-[2-(3-R-adamantan-1-yl)-2-oxoethylidene]hydrazinyl}-4-(het)aryl-4-oxobut-2-enoic acids

1-(3-R-adamantan-1-yl)-2-[(triphenyl-λ⁵-phosphanylidene)hydrazinylidene]ethanone reacted with 4-aryl(hetaryl)-2,4-dioxobutanoic acids to give 2-{2-[2-(3-R-adamantan-1-yl)-2-oxoethylidene]hydrazinyl}-4-aryl(hetaryl)-4-oxobut-2-enoic acids which were shown to exist in solution as mixtures of Z- and E-isomeric enehydrazine tautomers. The products underwent cyclization to 3-{[2-(3-R-adamantan-1-yl)-2-oxoethylidene]- hydrazinylidene}-5-aryl(hetaryl)furan-2(3H)-ones.     

Chemistry of iminofurans: X. Synthesis and hydrolysis of 5-aryl(hetaryl)-2-[(4,5,6,7-tetrahydro-1-benzothiophen-2-yl)imino]furan-3(2<Emphasis Type="Italic">H</Emphasis>)-ones

5-Aryl(hetaryl)furan-2,3-diones reacted with N-(triphenyl-λ⁵-phosphanylidene)-4,5,6,7-tetrahydro-1-benzothiophen-2-amines to give 5-aryl(hetaryl)-2-[(4,5,6,7-tetrahydro-1-benzothiophen-2-yl)imino]furan-3(2H)-ones whose acid hydrolysis afforded 4-aryl(hetaryl)-2-hydroxy-4-oxo-N-(4,5,6,7-tetrahydro-1-benzothiophen- 2-yl)but-2-enamides.     

Synthesis and reactions of 3-(3-ethoxycarbonyl-1-phenyl-1<Emphasis Type="Italic">H</Emphasis>-pyrazol-4-yl)propenic acid

The reaction of ethyl 4-formyl-1-phenyl-1H-pyrazole-3-carboxylate with the malonic acid led to the formation (2E)-3-(3-ethoxycarbonyl-1-phenyl-1H-pyrazol-4-yl)propenic acid. In reactions of this acid chloride with 4-amino-5-aryl(hetaryl)-4H-1,2,4-triazole-3-thiols were obtained ethyl 4-[(E)-2-{3-aryl(hetaryl)[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-6-yl}ethenyl]-1-phenyl-1H-pyrazoe-3-carboxylates, with 5-aryltetrazoles, ethyl 4-[(E)-2-(5-aryl-1,3,4-oxadiazol-2-yl)-ethenyl]-1-phenyl-1H-pyrazole-3-carboxylates, with 1-(2-hydroxy-3,5-dimethylphenyl) followed by the Baker-Venkataraman rearrangement and the cyclization, ethyl 4-[(E)-2-(6,8-dimethyl-4-oxo-4Hchromen-2-yl)ethenyl]-1-phenyl-1H-pyrazole-3-carboxylate.     

Novel route of the reaction of trifluoromethyl-containing N-methyl(4-ethoxyphenyl)imidazolidin-2-ones with urea

The reactions of perfluorobiacetyl with N-(4-ethoxyphenyl)- and N-methylurea afforded cis- and trans-isomers of 1-methyl-4,5-dihydroxy-4,5-bis(trifluoromethyl)imidazolidin-2-one and 1-(4-ethoxyphenyl)-4,5-dihydroxy-4,5-bis(trifluoromethyl)imidazolidin-2-one in a yield of ～60—75%. N-Alkyl(aryl)bis(trifluoromethyl)imidazooxazoles were obtained as unexpected products in the reaction of 1-alkyl(aryl)-4,5-dihydroxy-4,5-bis(trifluoromethyl)imidazolidin-2-ones with urea in dimethylacetamide. The reaction is accompanied by the rearrangement of imidazolidin-2-ones to N-alkyl(aryl)-5,5-bis(trifluoromethyl)hydantoins with CF₃ group migration from position 5 to position 4 of the starting heterocycle. A similar rearrangement is observed on boiling of the studied imidazolidin-2-ones in dimethylacetamide. The molecular structures of 3-(4-ethoxyphenyl)-5,5-bis(trifluoromethyl)imidazolidine-2,4-dione and 6-(4-ethoxyphenyl)-3a,6a-bis(trifluoromethyl)tetrahydroimidazo[4,5-d]oxazole-2,5-dione were studied by X-ray diffraction analysis.     

Efficient synthesis of new 1-alkyl(aryl)-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrol-2(5H)-ones

The synthesis of 1-alkyl(aryl)-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrol-2(5H)-ones 5, 6a-d from 1-alkyl(aryl)-4-bromo-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrolidin-2-ones 3, 4a-d is reported. The 1-alkyl(aryl)-4-bromo-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrolidin-2-ones 3, 4a-d were obtained from regiospecific bromination of 1-alkyl(aryl)-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrolidin-2-ones 1, 2a-d with molecular bromine. The NMR and X-ray diffraction data showed that 1-alkyl(aryl)-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrolidin-2-ones were brominated at 4-position in the pyrrolidin-2-one ring.     

Synthesis of 2-alkyl(aralkyl)sulfanyl-6-methylpyrimidin-4(3<Emphasis Type="Italic">H</Emphasis>)-ones and 4-alkyl(aralkyl)oxy-2-alkyl(aralkyl)sulfanyl-6-methylpyrimidines

2-Alkyl(aralkyl)sulfanyl-6-methylpyrimidin-4(3H)-ones and 4-alkyl(aralkyl)oxy-2-alkyl(aralkyl)-sulfanyl-6-methylpyrimidines having similar or different substituents on the sulfur and oxygen atoms were synthesized by alkylation of sodium salts derived from 6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidin-4-one and 2-alkyl(aralkyl)sulfanyl-6-methylpyrimidin-4(3H)-ones with alkyl (propyl, ethyl, allyl) and aralkyl [benzyl, m-phenoxybenzyl, p-(1-adamantylbenzyl)] halides. The effects of the alkyl (aralkyl) halide nature and solvent polarity on the rate of nucleophilic substitution and product yield were studied.     

Synthesis of substituted 2-(thiophen-2-yl)-1<Emphasis Type="Italic">H</Emphasis>-imidazol-1-ols

Substituted 2-(thiophen-2-yl)-1H-imidazol-1-ols were synthesized by cyclization of the corresponding α-thienyl nitrones in alkaline medium. α-Thienyl nitrones were obtained by reaction of N-(1-hydroxyimine-1-R-propan-2-yl)hydroxylamines with thiophene-2-carbaldehyde in methanol. At boiling α-thienyl nitrones in methanol in the presence of sodium methylate 5-aryl(hetaryl)-2-(thiophen-2-yl)-1H-imidazol-1-ols are formed chemoselectively.     

Synthesis of 4-alkyl(aryl,hetaryl)-2-thioxo-5,6,7,8-tetrahydroquinoline-3-carbonitriles and their derivatives by cross-recyclization of 4-alkyl(aryl,hetaryl)-2,6-diamino-4<Emphasis Type="Italic">H</Emphasis>-thiopyran-3,5-dicarbonitriles with 4-(cyclohex-1-en-1-yl)-morpholine,alkyl halides,and cyclohexanone

Cross recyclization of 4-substituted 2,6-diamino-4H-thiopyran-3,5-dicarbonitriles with 4-(cyclohex-1-en-1-yl)morpholine, alkyl halides, and cyclohexanone gave the corresponding substituted 2-thioxo-1,2,5,6,7,8-hexahydroquinoline-3-carbonitriles, 2-alkylsulfanyl-5,6,7,8-tetrahydroquinoline-3-carbonitriles, 3-amino-5,6,7,8-tetrahydrothieno[2,3-b]quinoline-2-carboxamides, and 4-oxo-2,2-pentamethylene-1,2,3,4,7,8,9,10-octahydropyrimido[4′,5′:4,5]thieno[2,3-b]quinolines. The structure of 3-(4-bromophenyl)-2,2-pentamethylene-11-(2-thienyl)-1,2,3,4,7,8,9,10-octahydropyrimido[4′,5′:4,5]thieno[2,3-b]quinoline was proved by X-ray analysis.     

Synthesis and structure of 2-ethoxy- and 2-aminomethylidene-3-fluoroalkyl-3-oxopropionates

Condensation of ethyl 3-polyfluoroalkyl-3-oxopropionates with excess triethyl orthoformate gave ethyl 3-polyfluoroalkyl-2-ethoxymethylidene-3-oxopropionates which reacted with primary aliphatic, aromatic, and heterocyclic amines to form ethyl 2-alkyl(aryl, hetaryl)aminomethylidene-3-polyfluoroalkyl-3-oxopropionates. According to the X-ray diffraction and IR data, the latter exist in the crystalline state as the corresponding E isomers, while in solution (NMR data), as mixtures of Z and E isomers. Condensation of ethyl 2-ethoxymethylidene-3-oxopropionates with secondary heterocyclic amines (morpholine and pyrrolidine) led to the formation of 2-morpholino(pyrrolidin-1-yl)methylidene-3-fluoroalkyl-3-oxopropionates which were shown to exist as Z isomers both in the crystalline state and in solution.     

Alkylation of 2-(methylsulfanyl)-6-polyfluoroalkylpyrimidin-4(3<Emphasis Type="Italic">H</Emphasis>)-ones with haloalkanes

The alkylation of ambident anions of 2-(methylsulfanyl)-6-(polyfluoroalkyl)pyrimidin-4(3H)-ones with 4-bromobutyl acetate leads to concurrent formation of O- and N-(4-acetoxybutyl) derivatives. Polar aprotic solvents favor formation of the O-isomer, and weakly polar dioxane favors N-alkylation. The reaction of 2-(methylsulfanyl)-6-(trifluoromethyl)pyrimidin-4(3H)-one with an equimolar amount of 1,2-dibromoethane in polar acetonitrile gives a mixture of N,N-, O,O-, and N,O-bridged bis-pyrimidines, as well as N- and O-[2-(methylsulfanyl)ethyl] derivatives, whereas in the presence of 10 equiv of 1,2-dibromoethane the N,O-isomer is formed as the only product. The reaction in weakly polar tetrahydrofuran yields N,N- and N,O-bispyrimidines.     

Dehydrogenation of 1-aryl(hetaryl)-1,2,3,4-tetrahydro-9<Emphasis Type="Italic">H</Emphasis>-β-carboline-3-carboxylic acids and their esters with dimethyl sulfoxide

Oxidative dehydrogenation of 1-aryl(hetaryl)-1,2,3,4-tetrahydro-9Н-β-carboline-3-carboxylic acids derivatives with dimethyl sulfoxide leads to the formation of 1-aryl(hetaryl)-9Н-β-carbolines. Simultaneously with the dehydrogenation decarboxylation occurs. At the oxidation with dimethyl sulfoxide of methyl 1-aryl (hetaryl)-1,2,3,4-tetrahydro-9Н-β-carboline-3-carboxylicates methyl 1-aryl(hetaryl)-9Н-β-carboline-3-carboxylates formed whose hydrolysis afforded the corresponding 1-aryl(hetaryl)-9Н-β-carboline-3-carboxylic acids.     

Synthesis of 9-Substituted 2-Alkyl(aryl)imidazo-[1,2-<Emphasis Type="Italic">a</Emphasis>]benzimidazole-3-carbonitriles

A one-pot preparative synthesis of 9-substituted 2-alkyl(aryl)imidazo[1,2-a]benzimidazole-3-carbonitriles from the corresponding 3-carbaldehydes and hydroxylamine O-sulfonic acid has been developed.     

New metal chelates of 5-amino-4-azopyrazoles: The crystal and molecular structure of bis{1-phenyl-3-methyl-4-(<Emphasis Type="Italic">p</Emphasis>-tolyl)azo-5-(<Emphasis Type="Italic">p</Emphasis>-carboxymethoxyphenyl)pyrazolamidato}copper(II)

The reactions of 1,3-alkyl(aryl) derivatives of 5-amino-4-azopyrazoles (HL) with copper(2+) acetate afford metal chelates CuL₂. Complexes with the CuN₄ chromophore containing a substituted amino group (X = NR) as a donor, like their azomethine analogues, have a pseudotetrahedral structure. Copper chelates with X = NH are planar. The X-ray diffraction data and an additional hyperfine structure (ahfs) from ¹⁵N atoms of the azo group in the labeled complexes provide evidence for the formation of six-membered metallocycles. The coordination polyhedron in bis{1-phenyl-3-methyl-4-(p-tolyl)azo-5-(p-carboxymethoxyphenyl)pyrazolamidato}Cu(II) can be described as a pseudotetrahedron.     

Reaction of <Emphasis Type="Italic">N</Emphasis>-alkyl(aryl)aminocarbonyl-1,4-benzoquinone monoimines with alcohols

Reactions of N-alkyl(aryl)aminocarbonyl-3,5-dimethyl-1,4-benzoquinone monoimines with alcohols led to the formation of products of 1,2-addition, quinolide compounds. They are the final products in reactions with alkyl derivatives, but in event of aryl derivatives they underwent cyclization with the subsequent elimination of the alcohol molecule to provide 4,7a-dimethyl-1-aryl-7,7a-dihydro-1H-benzimidazole-2,6-diones.     

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.     

Recyclization of 2,6-Diamino-4-aryl(cyclohexyl)-3,5-dicyano-4<Emphasis Type="Italic">H</Emphasis>-thio(seleno)pyrans

Recyclization of 2,6-diamino-4-aryl(cyclohexyl)-3,5-dicyano-4H-thio(seleno)pyrans in the presence of an equimolar amount of an α-bromo carbonyl compound, ethyl iodide, 1,2-dibromoethane, or 3-chlorophenyl isocyanate yields, respectively, 3-aryl(cyclohexyl)-2-[thiazol(selenazol)-2-yl]acrylonitriles, 6-amino-4-phenyl-2-ethylsulfanyl-1,4-dihydropyridine-3,5-dicarbonitrile, 5-amino-7-phenyl-2,3,4,7-tetrahydrothiazolo[3,2-a]pyridine-6,8-dicarbonitrile, or N,N′-bis(3-chlorophenyl)urea.     

Synthesis,characterization, and antimicrobial activity of novel (<Emphasis Type="Italic">E</Emphasis>)-1-(aryl)-3-{3, 5-dimethoxy-4-[(1-(aryl)-1<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazol-4-yl)methoxy]phenyl}prop-2-en-1-ones

The new chalcone derivatives containing the 1,2,3-triazole ring system, namely, (E)-1-(aryl)-3-{3,5-dimethoxy-4-[(1-(aryl)-1H-1,2,3-triazol-4-yl)methoxy]phenyl}prop-2-en-1-ones, were synthesized in 65–88% yield by the “click chemistry” reactions of substituted acetophenones, 4-hydroxy-3,5-dimethoxy-benzaldehyde, and different substituted azides. The structure of the compounds was determined by the FT-IR, ¹H NMR, ¹³C NMR, and mass spectroscopic analyses. Compounds 6a–6l were screened for in vitro antimicrobial activity by the agar disc diffusion method.     

Synthesis,spectroscopic characterization,crystal structures,and theoretical studies of (<Emphasis Type="Italic">E</Emphasis>)-2-(2,4-dimethoxybenzylidene)thiosemicarbazone and (<Emphasis Type="Italic">E</Emphasis>)-2-(2,5-dimethoxybenzylidene)thiosemicarbazone

Two thiosemicarbazones, (E)-2-(2,4-dimethoxybenzylidene)thiosemicarbazone (24-MBTSC (1)) and (E)-2-(2,5-dimethoxybenzylidene)thiosemicarbazone (25-MBTSC (2)), derived from 2,4-dimethoxybenzaldehyde and 2,5-dimethoxybenzaldehyde, respectively, with thiosemicarbazide have been synthesized and their structures were characterized by elemental analyses, FT-IR, ¹H NMR spectroscopy, and X-ray single-crystal diffraction analysis. Molecular orbital calculations have been carried out for 1 and 2 by using an ab initio method (HF) and also density functional method (B3LYP) at 6-31G basis set. Compound 1 crystallizes in the monoclinic system, space group P2₁/c, with a = 8.1342(5) Å, b = 18.1406(10) Å, c = 8.2847(6) Å, β = 109.7258(17)°, V = 1150.75(12) Å³, and Z = 4, whereas compound 2 crystallizes in the orthorhombic system, space group Pbca, with a = 11.0868(6) Å, b = 13.1332(6) Å, c = 15.9006(8) Å, V = 2315.2(2) Å³, and Z = 8. The compounds 1 and 2 displays a trans-configuration about the C=N double bond.     

Synthesis of 6,8-substituted 4-(hydroxyphenylamino)- and 4-(aminophenylamino)-2-methylquinolines

A procedure has been developed for the synthesis of 4-(hydroxyphenylamino)- and 4-(aminophenylamino)-2-methylquinolines having a substituent in the 6(8)-position of the quinoline ring from the corresponding 4-chloro-2-methylquinolines and o-, m-, and p-aminophenols and o-, m-, and p-phenylenediamines.     

4-aryl-2-hydroxy-4-oxobut-2-enoic acids <Emphasis Type="Italic">N</Emphasis>-(2-pyridyl)amides in reactions with diazo compounds

Reactions of 4-aryl-2-hydroxy-4-oxobut-2-enoic acids N-(2-pyridyl)amides with diazomethane, diazoethane, diaryldiazomethanes, and diazofluorene lead to the formation of 2-alkoxy-4-aryl-4-oxobut-2-enoic acids N-(2-pyridyl)amides, 3-aroyl-5-methylpyrazole-4-carboxylic acids N-(2-pyridyl)amides, and 3-alkoxy-3-(2-aryl-2-oxoethyl)-2,3-dihydro-2-oxoimidazo[1,2-a]pyridines. The composition and structure of compounds obtained depend on the nucleophilic nature of the diazo compound and on the character of substituents in the aryl and pyridine parts of the substrate.