Synthesis of 2-dichloromethyl-2-methyl [2-14C]-1,3-dioxolane

The labelled compound was prepared by chlorination of [2-¹⁴C]acetone obtained from the barium salt of [1-¹⁴C]acetic acid by pyrolysis. The reaction product 1,1-dichloro [2-¹⁴C]acetone was converted to 2-dichloromethyl-2-methyl [2-¹⁴C]-1,3-dioxolane by condensation with ethylene glycol in the presence of thionyl chloride. Radiochemical yield: 62% based on [1-¹⁴C]acetic acid.     

2-benzazepines. 10 [1]. New d-fused 2-benzazepines

Pyrano[3,2-d][2]benzazepines were synthesized by reaction of the beta-dimethylamino unsaturated ketone 1 with malonic ester or the anion of t-butyl acetate. Conversion of the pyrano derivative to the pyrido[3,2-d]-[2]benzazepine was achieved in low yield. A pyrrolo[3,2-d][2]benzazepine was prepared via an oxazepino-[6,7-d][2]benzazepine which was obtained by reaction of 1 with the anion of ethyl isocyanoacetate.     

Cyclopropanation of 2-arylmethylidenemalononitriles,alkyl 3-aryl-2-cyanoprop-2-enoates,and N-substituted 3-aryl-2-cyanoprop-2-enamides with bromine-containing zinc enolates

Zinc enolates derived from 2,2-dibromoindan-1-one and 2,2-dibromo-1,2,3,4-tetrahydronaphthalen-1-one reacted with 2-arylmethylidenemalononitriles, alkyl 3-aryl-2-cyanoprop-2-enoates, and N-substituted 3-aryl-2-cyanoprop-2-enamides to give, respectively, 3-aryl-1′-oxo-1′,3′-dihydrospiro[cyclopropane-1,2′-indene]-2-2-dicarbonitriles, 3-aryl-1′-oxo-3′,4′-dihydro-1′H-spiro[cyclopropane-1,2′-naphthalene]-2,2-dicarbonitriles, alkyl 3-aryl-2-cyano-1′-oxo-1′,3′-dihydrospiro[cyclopropane-1,2′-indene]-2-carboxylates, alkyl 3-aryl-2-cyano-1′-oxo-3′,4′-dihydro-1′H-spiro[cyclopropane-1,2′-naphthalene]-2-carboxylates, and N-substituted 3-aryl-2-cyanol-1′-oxo-3′,4′-dihydro-1′H-spiro[cyclopropane-1,2′-naphthalene]-2-carboxamides as a single diastereoisomer. The stereoconfiguration of the products was determined by ¹H and ¹³C NMR spectroscopy.     

Simple Ligand Effects Switch a Hydrogenase Mimic between H2 and O2 Activation

Herein, we report a [NiRu] biomimetic system for O₂‐tolerant [NiFe]hydrogenases and demonstrate that electron donation to the [NiRu] center can switch the system between the activation of H₂ and O₂ through simple ligand effects by using hexamethylbenzene and pentamethylcyclopentadienyl ligands, respectively. Furthermore, we present the synthesis and direct observations of a [NiRu]–peroxo species, which was formed by the oxygenation of a Ni‐SIa model [NiRu] complex, that we propose as a biomimetic analogue of O₂‐bound species (OBS) of O₂‐tolerant [NiFe]hydrogenases. The [NiRu]–peroxo complex was fully characterized by X‐ray analysis, X‐ray photoelectron spectroscopy (XPS), mass spectrometry, and ¹H NMR spectroscopy. The OBS analogue was capable of oxidizing p‐hydroquinone and sodium borohydride to turn back into the Ni‐SIa model complex.     

Cs[Me2GaF2], ein solvensfreies Caesiumsalz des einfachsten Diorganodifluorogallats

Cs[Me₂GaF₂], a Solvent-free Caesium Salt of the Plainest Diorganodifluoro Gallate The metalate Cs[Me₂GaF₂] ( 1 ), obtained by the reaction of Cs[Me₃GaF] with H₂O in THF and recrystallized from toluene, was characterized by an X-ray structure determination. According to the structure analysis, 1 consists of puckered layers of Cs[Me₂GaF₂] stacked along [001].     

Peri-selective photocycloadditions of methyl 2-pyrone-5-carboxylate with unsaturated cyclic ethers

Photosensitized cycloaddition reaction of methyl 2-pyrone-5-carboxylate ( 1 ) with 2,3-dihydrofuran gave cis- exo- and cis-endo-[2 + 2] cycloadducts across the C₃-C₄ double bond in 1 , and a [4 + 2] cycloadduct which was different in addition-orientation from the Diels-Alder adducts. Each [2 + 2] cycloadduct was obtained by the use of sensitizers having different triplet energies. Photosensitized reactions of 1 with 3,4-dihydro-2H-pyrans afforded cis-endo-[2 + 2] cycloadducts, respectively. The photocycloaddition mechanism was also explained from the excited state of 1 calculated by means of MNDO-Cl method.     

Cyclisation of 4-[2-Cyclofentenyl]-3-Hydroxy [1] Benzopypan-2-One

4-[2-cyclopentenyl]-3-hydroxy [1] bonzopyran-2-one(3) was cyclised to the bicyclie coumar in-1,3-ethano-2-bromo-1,2-dihydro-3H-pyrano [2,3-c] [1] benzopyran-5-one (6) by a sequence of reactions viz. acetylation of 3, addition of bromine to cyclopenteny double bond and treating the resulting acetyldibromo compound (5) with 4% alcoholic KOH, Cyclisation of compound (3) with mercuric acetate in methanol gave condensed furan derivative 7 which on reductive demercuration with zinc borohydride in dimethoxyethane gave the 1,3-propano-1,2-dihydrofuro [2,3-c] [1] benzopyran-4-one, 8. Cyclisation of compound 2 with come. H₂SO₄ furnished a mixture of bicyclic derivative 9 ad furo coumarin derivative 8.     

Synthese und Kristallstruktur von [(PhCH2)2GaF(tBuNH2)]2 · 2 THF

Synthesis and Crystal Structure of [(PhCH₂)₂GaF(^tBuNH₂)]₂ · 2 THF (PhCH₂)₂GaF reacts with ^tBuNH₂ to the adduct [(PhCH₂)₂GaF(^tBuNH₂)] ( 1 ). 1 was characterized by NMR, IR and MS techniques. 1 can be recrystallized from THF forming crystals of [ 1 ]₂ · 2 THF. According to an X-ray structure analysis [ 1 ]₂ · 2 THF consists of dimers of 1 formed by hydrogen bridges. The THF molecules are coordinated to [ 1 ]₂ by hydrogen bridges, too.     

Synthesis of [2-(vinyloxy)ethyl]uracil and [2-(allyloxy)ethyl]uracil

A synthesis is reported for N¹-mono- and N¹,N³-disubstituted uracil derivatives containing a terminal carbon-carbon double bond in the side-chain. Alkylation of vinyl 2-chloroethyl ether by uracil potassium salts leads to a mixture of 1-[2-(vinyloxy)ethyl] and 1,3-di[2-(vinyloxy)ethyl] derivatives while treatment of 2,4-bis(trimethylsilyloxy)pyrimidines by vinyl 2-chloroethyl ether leads exclusively to N¹-monosubstituted products. Alkylation of cytosine by this chloroether gave 1-[2-(vinyloxy)ethyl]cytosine. The synthesis of 1-[2-(allyloxy)ethyl]uracil derivatives was carried out by treatment of uracil potassium salts by 1-(allyloxy)-2-(p-toluenesulfonyloxy)ethane.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 393–397, March, 1993.     

Boron coordination compounds derived from 2-phenyl-benzimidazole and 2-phenyl-benzotriazole bidentate ligands

The syntheses and structural analyses of a series of boron heterocycles derived from 2-(1H-benzimidazol-2-yl)-phenylamine (1), 2-(1H-benzimidazol-2-yl)-phenol (2), 2-(1H-benzimidazol-2-yl)-benzenedisulfide (3), 2-[3-(1,1,1,3,-tetramethyl-butyl)-phenyl]-2H-benzotriazole (4), 2-[3,5-bis-(1-methyl-1-phenylethyl)-phenyl]-2H-benzotriazole (5) and (C₆H₅)₂BOH or BF₃·OEt₂ are reported. The new boron compounds: diphenyl-[2-(1H-benzimidazol-2-yl-κN)-phenylamide-κN]-boron (6), diphenyl-[2-(1H-benzimidazol-2-yl-κN)-phenolate-κO]-boron (7), diphenyl-[2-(1H-benzimidazol-2-yl-κN)-benzenethiolate-κS]-boron (8), diphenyl-[2-(2H-benzotriazol-2-yl-κN)-4-(1,1,3,3-tetramethyl-butyl)-phenolate-κO]-boron (9), diphenyl-[2-(2H-benzotriazol-2-yl-κN)-4,6-(1-methyl-1-phenylethyl)-phenolate-κO]-boron (10), difluoro-[2-(1H-benzimidazol-2-yl-κN)-phenolate-κO]-boron (11), difluoro-[2-(2H-benzotriazol-2-yl-κN)-4-(1,1,3,3-tetramethylbutyl)-phenolate-κO]-boron (12) and difluoro-[2-(2H-benzotriazol-2-yl-κN)-4,6-(1-methyl-1-phenylethyl)-phenolate-κO]-boron (13) have four fused rings, with boron included in a six-membered ring and bound to N, O or S atoms and strongly coordinated by a nitrogen atom from the imidazole or triazole rings. Their structures are zwitterionic, with a negative charge on the boron and a delocalized positive charge on the ligand. Compounds 6-12 were studied by NMR, IR, mass spectrometry, and 6-10 and 12 by X-ray diffraction analyses.     

Modification of 2-trifluoromethyl-1H-benzimidazole with hydroxyalkyl substituents

Alkylation of 2-(trifluoromethyl)-1H-benzimidazole with 4-bromobutyl acetate gave 4-[2-(trifluoromethyl)-1H-benzimidazol-1-yl]butyl acetate which was deacylated by the action of hydrogen chloride in anhydrous ethanol. 4-[2-(Trifluoromethyl)-1H-benzimidazol-1-yl]butan-1-ol thus formed showed a moderate tuberculostatic activity. Alkylation of the title compound with chloromethyloxirane afforded a mixture of 1-chloro-3-[2-(trifluoromethyl)-1H-benzimidazol-1-yl]-propan-2-ol and 1-(oxiran-2-ylmethyl)-2-trifluoromethyl-1H-benzimidazole. A new procedure was proposed for the synthesis of 2-[(2-trifluoromethyl-1Hbenzimidazol-1-yl)methoxy]ethyl acetate.     

Synthesis of 2, 2, 4-trimethyl-1, 3-pentaerediol monoisobutyrate catalyzed by homogeneous catalysis-liquid/liquid separation catalytic system based on Bibasic sites Ionic Liquids

Herein a novel homogeneous catalysis-liquid/liquid separation catalytic system based on 1, 8-diazabicyclo-[5.4.0] undec-7-ene (DBU)-functionalized, 1, 1, 3, 3-tetramethyl guanidine-functionalized and imidazolium-functionalized bibasic sites ionic liquids (BSILs) ([HDBU]IM, [Aemim]IM, [TMG]IM, [Aemim]Pro, [Aemim]Gly, [HDBU]Pro and [HDBU]Gly) with a room temperature liquid/liquid phase transition characteristic were reported. And for the first time, this novel catalytic system was employed for the synthesis of 2, 2, 4-trimethyl-1, 3-pentaerediol monoisobutyrate (CS-12), achieving homogeneous catalysis, easy recycling and long service-life of the catalyst. Additionally, the mechanism of homogeneous catalysis-biphasic separation might be explained by the solubility of reactant and product in BSILs/H₂O catalytic system and the existence H-bonding between BSILs and H₂O. Bibasic sites were confirmed by two endothermic peaks on the TG-DCS curve of [Aemim]IMC (the CO₂ captured by [Aemim]IM).     

Über die Synthese von 1-Aryl-und 1-Alkyl-2, 3-dimethyl-chinoxalinium-perchloraten. 2. Mitteilung. Synthese und 1H-NMR.-Spektren von 2,3-Dimethyl-1-phenyl-6-X-chinoxalinium-perchloraten

On the Synthesis of 1-Aryl- and-1-Alkyl-2, 3-dimethyl-quinoxalinium Perchlorates. 2nd Communication

1 1. Mitt.: [1].

. Synthesis and ¹ H-NMR. Spectra of 2, 3-Dimethyl-1-phenyl-6-X-quinoxlinium Perchlorates The synthesis of the title compounds ( 5 ) which have been useful as precursors for a lot of conventional and new-type dyes [2-8] has yet been limited to examples with X?H [2] [3] [11] [15] and with electron-donating [4] [12] or at best slightly electron-accepting [1] [6] substituents X and R. We now describe a method suitable even for compounds 5 with strongly electron-accepting substituents: N-monosubstituted o-phenylendiamines 4 , were condensed with 2, 3-butanedione and perchloric acid in mixed solvents containing an excess of diethyl ether. The products - mostly substituted at position 6 of the quinoxalinium ring - are chracterized by ¹H-NMR. spectra, elemental analyses and in most cases by isolation of the corresponding bases 6 . Correlations of chemical shifts with Hammett's σ_p [18] are given by equations (1)-(5).     

Synthesis of 2-Acetoxy- and 2-Hydroxy-2,3-dihydronaphtho[1,8-bc]pyran

Summary 2-Acetoxy- and 2-Hydroxy-2,3-dihydronaphtho[1,8-bc]pyranes were synthesized by decomposition of 1-hydroperoxy-1,2-dihydroacenaphthylene in acetic acid in the presence of perchloric acid.

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Synthese von 2-Acetoxy- und 2-Hydroxy-2,3-dihydronaphtho[1,8-bc]pyran

Zusammenfassung 2-Acetoxy- und 2-Hydroxy-2,3-dihydronaphtho[1,8-bc]pyrane konnten durch Zersetzung von 1-Hydroperoxy-1,2-dihydroacenaphthylen in Essigsäure in Anwesenheit von Perchlorsäure synthetisiert werden.

     

Some reactions of 2H-[1]benzothieno[3,2-b]pyran-2-ones and related compounds

The conversion of 2H-[1]benzothieno[3,2-b]pyran-2-ones into mono- and dithio-derivatives and the preparation of some dibenzothiophenes, sulphines and pyridones are described.

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Einige Reaktionen von 2H-[1]Benzothieno[3,2-b]pyran-2-onen und verwandten Verbindungen

Zusammenfassung Es wird die Umsetzung von 2H-[1]benzothieno[3,2-b]pyran-2-onen zu Monound Dithio-Derivaten und die Darstellung einiger Dibenzothiophene, Sulfine, und Pyridone beschrieben.

     

Cyclocondensation of 3-amino-2-iminonaphtho[1,2-d]thiazole with oxalic acid derivatives

Refluxing 3-amino-2-iminonaphtho[1,2-d]thiazole ( 1 ) with diethyl oxalate ( 2a ) in a 2:1 molar ratio in dry pyridine provided 2,2′-binaphtho[1′,2′:4,5]thiazolo[3,2-b][1,2,4]triazole ( 3 ). On the other hand, when 1 was treated with excess amount of 2a in dimethylformamide, it afforded ethyl naphtho[1′,2′:4,5]thiazolo[3,2-b][1,2,4]triazole-2-carboxylate ( 4a ) on heating and ethyl N-(2-iminonaphtho[1,2-d]thiazol-3-yl)oxamate ( 5 ) by stirring at room temperature. Cyclization of 5 upon fusion led to the formation of 3-hydroxy-2H-naphtho-[1′,2′:4,5]thiazolo[3,2-b][1,2,4]triazin-2-one ( 6 ). Compound 6 could also be prepared directly from 1 by refluxing either with 2a neatly, in glacial acetic acid or with oxalic acid ( 2b ) in the same medium. The acid form of 4a might be obtained from 1 and 2b on heating in dimethylformamide, but it was decarboxylated to naphtho-[1′,2′:4,5]thiazolo[3,2-b][1,2,4]triazole ( 4b ) during the reaction.     

The synthesis of novel polycyclic heterocyclic ring systems. 3. Synthesis and NMR spectroscopy of 15-chloro[1]benzo-thieno[2″,3″:3′,4′]naphtho[1′,2′:4,5]thieno[2,3-c]quinoline

The polycyclic heterocyclic compound with a novel ring system, 15-chloro[1]benzothieno[2″,3″:3′,4′]-naphtho[1′,2′:4,5]thieno[2,3-c]quinoline was synthesized via photocyclization of 3-chloro-N-phenyl[1]-benzothieno[2′,3′:3,4]naphtho[2,1-b]fhiophene-2-carboxamide followed by chlorination with phosphorus oxychloride. The assignment of its ¹H and ¹³C nmr spectra was accomplished by utilizing two-dimensional nmr methods.     

The synthesis and properties of ferroceno[1′,2′;1″,2″]bis(1,3-dithiol-2-thione and -2-one) derivatives

The t-butyl and bis(t-butyl) derivatives of hexathia[3.3]ferrocenophane were prepared from the corresponding trithia[3]ferrocenophanes. The former was a mixture of chair-chair and chair-boat isomers, and the latter existed only chair-boat isomer. The hexathia[3.3]ferrocenophanes were led to the tetrathiols with LiAlH₄, which allowed to react with 1,1′-thiocarbonyldiimidazol to give the corresponding ferroceno[1′,2′;1″,2″]bis(1,3-dithiol-2-thione) derivatives. Mono t-butyl and unsubstituted analogs were prepared in a similar manner. The X-ray structural determination showed that these derivatives adopted the conformation in which the 1,3-dithiol-2-thione rings were heaped on top of each other. In the crystal of ferroceno[1′,2′;1″,2″]bis(1,3-dithiol-2-thione), the molecules packed so as to put the axis of molecule in order and to overlap one another above and below. The desulfurizative coupling of the ferroceno[1′,2′;1″,2″]bis(1,3-dithiol-2-thione) derivatives was unsuccessful.     

Synthesis,characterization, and DNA binding of ruthenium(II) complexes with 2-benzo[b] furan-2-yl-1H-imidazo[4,5f][1,10]phenanthroline as an intercalative ligand

DNA-binding properties of a number of ruthenium complexes with different polypyridine ligands are reported. The new polypyridine ligand BFIP (=2-benzo[b] furan-2-yl-1H-imidazo[4,5-f][1,10]phenanthroline) and its ruthenium complexes [Ru(bpy)₂BFIP]²⁺ (bpy = 2,2′-bipyridine), [Ru(dmb)₂BFIP]²⁺ (dmb = 4,4′-dimethyl-2,2′-bipyridine), and [Ru(phen)₂BFIP]²⁺ (phen = 1,10-phenanthroline) have been synthesized and characterized by elemental analysis, mass spectra, IR, UV-Vis, ¹H- and ¹³C-NMR, and cyclic voltammetry. The DNA binding of these complexes to calf-thymus DNA (CT-DNA) was investigated by spectrophotometric, fluorescence, and viscosity measurements. The results suggest that ruthenium(II) complexes bind to CT-DNA through intercalation. Photocleavage of pBR 322 DNA by these complexes was also studied, and [Ru(phen)₂BFIP]²⁺ was found to be a much better photocleavage agent than the other two complexes.     

Reaction of 2-hydrazinoperimidine with acetylacetone

Heating 2-hydrazinoperimidine ( 2 ) with acetylacetone in absolute ethanol gave exclusively 2-(3,5-dimethyl-1-pyrazolyl)perimidine ( 4 ) via a [2 + 3] cyclization. The possible [4 + 3] condensate, 3,5-dimethyl-1H-1,2,4-triazepino[4,3-a]perimidine ( 5 ) was not produced. Spectral analyses were applied to the structure elucidation of the products.