Catalytic reduction of 2-thiophenaldehyde and 2-acetothienone

A catalyst, rhenium heptasulfide, has been found for reducing 2-thiophenaldehyde and 2-acetylthiophene to the corresponding alkylthiophenes. The reduction conditions found were: temperature 170° -190° C, hydrogen pressure 130 atm, time 3–6 hr. Reduction of 2-thiophenaldehyde in methanol in the presence of rhenium heptasulfide gives 2-methoxythiphene, while corresponding hydrogenation of 2-acetylthiophene in ammonia plus dioxane gives 2-( -aminoethyl) thiophene.     

Beckmann rearrangement of acetylthiophene oxime benzenesulfonates as a method for the synthesis of acetamidothiophenes

The Beckmann rearrangement of 2-acetylthiophene, 5-methyl-2-acetylthiophene, 5-chloro-2-acetylthiophene, and 2,5-dichloro-3-acetylthiophene oxime benzenesulfonates to the corresponding acetamidothiophenes was carried out by heating with an aqueous methanol solution of sodium acetate. This method can be used for the preparative synthesis of 2-acetamidothiophene and 2,5-dichloro-3-acetamido-thiophene.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 483–485, April, 1985.     

Reactions of aromatic and heteroaromatic compounds carrying electron-acceptor substituents. 26. Acylaminomethylation of 2-acylthiophenes, 2-thiophenecarboxylic acid,and its esters

The reaction of 2-thiophene aldehyde, 2-acetylthiophene, 2-thiophene carboxylic acid, and its methyl ester with N-(hydroxymethyl)chloroacetamide in concentrated sulfuric acid yields a mixture of 4- and 5-(N-chloroacetylamino) methyl derivatives, the former being preferred.For Communication 25, see [1].Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 793–797, June, 1986.     

1,4-Benzodiazepines and their derivatives

A series of compounds of the merocyanine dye type was obtained by the reaction of 1-acetyl-1,3-dihydro-2H-1,4-benzodiazepin-2-ones and 1,3-dihydro-2H-1,4-benzodiazepine-2-thiones with 2-methylmercapto-3-ethylbenzothiazolium tosylate, 2-methylmercapto-3,4,5-trimethylthiazolium bromide, 2-methylmercapto-3-methyl-5-phenyloxazolium methosulfate, and 1,3,3-trimethyl-2-formylmethyleneindoline. The hydrogen atoms of the methylene group of the 1-unsubstituted and 1-alkyl-substituted 1,3-dihydro-2H-1,4-benzodiazepin-2-ones are of low mobility, and the indicated compounds do not undergo condensation reactions with electrophilic agents.See [6] for communication VI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 992–994, July, 1971.     

Synthesis of heterocycles on the basis of arylation products of unsaturated compounds. 19.* Arylation of 2-acetylthio- phene and the synthesis of 2-(5-aryl-2-thien- yl)-4-quinolinecarboxylic acids

The reaction of 2-acetylthiophene with acetylthiophene with arenediazonium chlorides in the presence of cupric chloride as catalyst gives 2-acetyl-5-arylthiophenes. These products react with 5-chloro- and 5-bromoisatins to give 6-chloro- and 6-bromo-substituted 2-(5-aryl-2-thienyl)-4-quinolinecarboxylic acids.     

Benzoylation of deactivated compounds of the thiophene and furan series with phenyldichlorocarbenium tetrachloroaluminate

The reactions of benzotrichloride with methyl and ethyl esters and nitriles of 2-thiophenecarboxylic and 2-furancarboxylic acids, with 2-acetylthiophene, 2-acetylfuran, and 2-thiophenaldehyde in the presence of an excess of anhydrous aluminum chloride have been studied. The phenyldichloromethyl group enters into position 4 of the thiophene and position 5 of the furan ring and on treating the reaction mixture with water is converted to benzoyl group.Dedicated to Professor M. A. Yurovskaya on her Jubilee.N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences (RAN), Moscow 117913 Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3. pp. 315–323, March, 2000.     

Reaction of the N,N-dimethylamide and methyl ester of 3-phenyl-3-chloro-2-ketopropionic acid with triphenylphosphine

Conclusions The dimethylamide of 3-phenyl-3-chloro-2-ketopropionic acid reacts with Ph₃P to give -(N,N-dimethyloxamoyl)benzyltriphenylphosphonium chloride. In the presence of methanol, this reaction gives dimethyl(phenylpyruvoyl)amide and Ph₃PO.2. The methyl ester of 3-phenyl-3-chloro-2-ketopropionic acid reacts with Ph₃P to give methoxycarbonylstyryloxytriphenylphosphonium chloride, which, upon heating in benzene at reflux, gives methyl -chlorocinnamate and Ph₃PO.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1395–1396, June, 1989.     

Synthesis and structure of mixed-metal thiolate complex Cp′Cr(CO)2(μ-SBu)Pt(PPh3)2: Side-on-coordination of Cr–S double bond with platinum

The reaction of [Cp′Cr(CO)₂(μ-SBu)]₂ (1) (Cp′ = MeC₅H₄) with (PPh₃)₂Pt(PhCCPh) gives Cp′Cr(CO)₂(μ-SBu)Pt(PPh₃)₂ (2) which could be regarded as a product of the substitution of acetylene ligand at platinum by a monomeric chromium–thiolate fragment. According to the X-ray diffraction analysis 2 contains single Cr–Pt (2.7538(15)) and Pt–S (2.294(2) Å) bonds while Cr–S bond (2.274(3) Å) is shortened in comparison with ordinary Cr–S bonds (2.4107(4)–2.4311(4) Å) in 1. The bonding between Cr–S fragment and platinum atom is similar to the olefine coordination in their platinum complexes.     

Kinetics and mechanism of the decomposition of Cs2Pt[CH3]2Cl4 in aqueous solution with concurrent formation of C2H6, C2H4, and C2H5Cl

Reductive elimination of ethane from Cs₂Pt(CH₃)₂Cl₄ in aqueous chloride solutions at 368 K is accompanied by C-H bond scission. A mechanism is proposed for the reaction which includes the intermediate formation of an ethylhydrideplatinum(IV) and an ethylplatinum(II) complex.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 29, No. 2, pp. 154–158, March–April, 1993.     

Bromination of 2-acetylthiophene and its derivatives

A new method has been developed for the bromination of thiophene and its derivatives. The method consists in the action of N-bromosuccinimide in acetic anhydride and glacial acetic acid on the thiophene derivatives. In the bromination of 2-acetylthiophene and its derivatives, the bromine replaces the hydrogen atom in the 5 position of the thiophene ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 185–187, February, 1973.     

Oxidation of aliphatic alcohols by a system containing Na2S2O8 and a metal chloride

Conclusions The oxidation of primary aliphatic alcohols by the Na₂S₂O₈-alkali metal chloride system in water in the presence of sulfuric acid gives 1,1-dialkoxy-2-chloroalkanes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1932–1934, August, 1988.     

The phase diagram and supercooling conditions for the Ca(NO3)2−CaCl2−H2O system

The liquidus temperature and induction periods were measured for crystallization in a system of calcium nitrate, calcium chloride, and water over a concentration range of 5–20 mole% Ca(II), i.e., R=4–18 [R=moles H₂O/moles Ca(II)] and y_cl=0–1 [y_cl=moles Cl^–/moles (NO ₃ ^– +Cl^–)]. A ternary phase diagram was constructed, and qualitative dependences of the supercooling at which the solution began to crystallize on the system composition were found. A wide range of stability toward crystallization was found for solutions withR=4–10 and y_cl=0–0.7 The relationships between the system stability toward crystallization and the viscosity, glass-transition temperature, and the liquidus temperature are discussed.     

Fluorometric Determination of Fructose, Glucose, and Sucrose Using Zirconyl Chloride

Zirconyl chloride upon hydrolysis in water to form Zr(OH)⁺ has been found to react to form a fluorescent derivative with not only a ketose such as fructose but also a hexose such as glucose and the disaccharide sucrose. When reaction conditions such as a temperature of 99°C and a time of 60 min are used, detection limits below 1 μg/mL are possible. All three zirconyl–sugar derivatives show very similar absorbance and fluorescence spectra, indicating a common mechanism involving formation of an enediol which can be complexed with ZrOH⁺ is likely. Because the reactivity order is glucose < sucrose < fructose, the reaction can be made selective for fructose at a lower reaction temperature and time such as 60°C at 5 min. Because interference from ascorbic acid and caffeine is also avoided, the fluorescent determination of fructose in soft drink samples after simply a dilution step is possible. We have also employed this reaction for flow injection analysis (FIA) using a polystyrene–divinylbenzene-packed HPLC column as a mixing device. Using a 0.01 M HClO₄ with 1% zirconyl chloride carrier, we obtained a linear calibration curve from 2 to 30 μg/mL with a correlation coefficient of 0.994. A detection limit less than 2 μg/mL was possible. A comparison of results for the FIA of soft drinks with the enzymatic method involving fructose-5-dehydrogenase confirmed the FIA method was quite specific for fructose.     

Thermodynamic Model for the Solubility of TcO2· xH2O(am) in the Aqueous Tc(IV) – Na+ – Cl− – H+ – OH− – H2O System

Solubility studies of TcO₂· xH₂O(am) have been conducted as a function of H⁺ concentration from 1 × 10^{– 5} to 6 M HCl and as a function of chloride concentration from 1 × 10^{– 3} to 5 M NaCl. These experiments were conducted under carefully controlled reducing conditions such that the preponderance of Tc present in solution is in the reduced oxidation state and was determined to be Tc(IV) by XANES analysis. The aqueous species and solid phases were characterized using a combination of techniques including thermodynamic analyses of solubility data, XRD, and XANES, EXAFS, and UV-vis spectroscopies. Chloride was found to significantly affect Tc(IV) concentrations through (1) the formation of Tc(IV) chloro complexes [i.e., TcCl₄(aq) and TcCl₆ ^{2 –}] and a stable compound [data suggests this compound to be TcCl₄(am)] in highly acidic and relatively concentrated chloride solutions, and (2) its interactions with the positively charged hydrolyzed Tc(IV) species in solutions of relatively low acidity and high chloride concentrations. A thermodynamic model was developed that included hitherto unavailable chemical potentials of the Tc(IV)–chloro species and Pitzer ion-interaction parameters for Tc(IV) hydrolyzed species with bulk electrolyte ions used in this study. The thermodynamic model presented in this paper is consistent with the extensive data reported in this study and with the reliable literature data and is applicable to a wide range of H⁺ and Cl^– concentrations and ionic strengths.     

1, 2-Dithiolium salts

A new method for the synthesis of 1, 2-dithiolium hydrogen sulfates by the oxidation of 1, 2-dithiole-3-thiones with hydrogen peroxide in acetic acid has been developed. From 4-(p-tolyl) 1, 2-dithiolium hydrogen sulfate a series of salts containing anions of inorganic, heteroorganic, and organic acids (Cl^–, Br^–, I^–, ClO ₄ ^– , CNS^–, VO ₃ ^– , HMoOO ₄ ^– , S₂O ₃ ^2– , S₂O ₈ ^2– , Cr₂O ₇ ^2– , Fe(CN) ₆ ^3– , Fe(CN) ₆ ^4– , B(C₆H₅) ₄ ^– , F₃CCOO^–, C₆H₂(NO₂)₃O^–) has been obtained. 4-(p-tolyl)-1, 2-dithiolium salts containing the anions NO ₂ ^– , NO ₃ ^– , ClO ₃ ^– , BrO ₃ ^– , SO ₃ ^2– , SO ₄ ^2– , S₂O ₅ ^2– and Cl₃CCOO^– dissolve in water and do not precipitate in double decomposition reactions. The reactions of 4-(p-tolyl)-1, 2-dithiolium hydrogen sulfate with sodium sulfite, disulfide, and hydrogen sulfide lead to the formation of bis[4-(p-tolyl)-1, 2-dithiol-3-yl] sulfide and disulfide and the sodium salt of 4-(p-tolyl-1, 2-dithiole-3-thiol, respectively. The reaction of 4-(p-tolyl)-1, 2-dithiolium hydrogen sulfate with solutions of salts of the alkali metals containing the anions of weak acids F^–, CNO^–, HCO ₃ ^– , CO ₃ ^2– , B₄O ₇ ^2– , HAsO ₄ ^2– , PO ₄ ^3– , CH₃COO^–, ClCH₂COO^–, etc.) forms bis[4-(p-tolyl)-1, 2-dithlol-3-yl] oxide. [8, Table 3].For part I, see [1].     

Reactions of 2-oxo-2-dialkylamino-1,2-oxaphospholanes with acid chlorides

The reaction of acetyl chloride, chloroacetyl chloride, benzoyl chloride, and phosphorus trichloride with 2-oxo-2-dialkylamino-1,2-oxaphospholanes gives 2-oxo-2-chloro-1, 2-oxaphospholanes. Phosphorus pentachloride opens the 1,2-oxaphospholane ring with the formation of dimethylamido-3-chloroalkylphosphonyl chloride.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1433–1434, June, 1990.     

Enthalpies of combustion and formation of 2-acetylpyrrole, 2-acetylfuran and 2-acetylthiophene

The combustion energies for 2-acetylpyrrole (cr) and 2-acetylfuran (cr) were determined using a static bomb calorimeter, whereas the combustion energy of 2-acetylthiophene (l) was determined with a rotating bomb calorimeter; both calorimeters have been recently described. The molar combustion energies obtained were: −(3196.1 ± 0.6) kJ mol⁻¹ for 2-acetylpyrrole, −(2933.8 ± 0.7) kJ mol⁻¹ for 2-acetylfuran, and −(3690.4 ± 0.8) kJ mol⁻¹ for 2-acetylthiophene. From these combustion energy values, the standard molar enthalpies of formation in the condensate phase were obtained as: −(163.51 ± 0.97) kJ mol⁻¹, −(283.50 ± 1.06) kJ mol⁻¹ and −(123.93 ± 1.15) kJ mol⁻¹, respectively. The obtained values of combustion and formation enthalpies of 2-acetylthiophene are in concordance with the reported previously. For the two last compounds, polyethene bags were used as an auxiliary material in the combustion experiments. The heat capacities and purities of the compounds were determined using a differential scanning calorimeter.     

(N,N, N′, N′-tetramethylethylenediammonium)Cu2X6 (X=Cl,Br): crystal structure and magnetic interactions

Summary The crystal structures of (Me₄enH₂)Cu₂Cl₆ and (Me₄enH₂)Cu₂Br₆ have been determined. The triclinic crystals contain chains of symmetrically bibridged [Cu₂X₆]^2– dimers. Within the dimers the Cu–X distances average 2.299 Å (Cl) and 2.408 Å (Br) and the Cu–X–Cu angles are 96.4(1)^o (Cl) and 95.7(1)^o (Br). Longer Cu–X bonds, 2.679(1)Å (Cl) and 2.761(3)Å (Br), link dimers together into infinite chains via asymmetrical bridges. The bridging angles for the asymmetric bridge are 92.2(1)^o (Cl) and 89.4(1)^o (Br). Magnetic susceptibility data for both compounds are indicative of antiferromagnetic coupling. Analyses of the data yields J/k=–23(1)K (Cl) and –82(2)K (Br) for the interdimer coupling and J/k=–5(1)K (Cl) and –4(1)K (Br). The intradimer coupling for the chloride is in accord with magneto-structure relations deduced for similar salts. Similarly, the increased antiferromagnetic contribution upon substitution of Cl by Br follows trends previously observed.     

Heterogeneous isotope exchange reaction between SnCl2 and SnO2·xH2O in HCl medium

Heterogeneous isotope exchange between hydrated stannic oxide and stannous chloride in 0.1M HCl solution has been studied as a function of the stannic oxide, stannous chloride, and chloride ion concentrations, and temperature. The exchange process is a second-order reaction, which is independent of the chloride ion concentration, with a mean rate constant, k, of 2.31 dm³ mol^–1·min^–1. The activation energy of the isotope exchange process was found to equal 3.62 kcal·mol^–1. Possible use of this system, SnCl₂/SnO₂·xH₂O, as basis for a¹¹³Sn-^113mIn generator is suggested.