Structure of 3-(o-hydroxyphenyl) derivatives of 2-quinoxalone and 2-benzoxazinone

It is shown by IR and UV spectroscopy that the products of the reaction of o-hydroxybenzoylformic acid with o-phenylenediamine and o-aminophenol have the 3-(cyclohexa-3,5-dien-2-onylidene)quinoxalone structure rather than the 3-(o-hydroxyphenyl)-2-quinoxalone structure. 3-(o-Methoxyphenyl)-2-quinoxalone and 3-(o-methoxyphenyl)-3,4-dihydro-2H-benzo-1,4-oxazin-2-one were synthesized as model compounds.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1126–1128, August, 1977.     

Über Chalkogenolate. 81. Untersuchungen über N-Hydroxydithiocarbamidsäure 3. Ester der N-Hydroxydithiocarbimidsäure und -carbamidsäure

On Chalcogenolates. 81. Studies on N-Hydroxy Dithiocarbamic Acid. 3- Esters of N-Hydroxy Dithiocarbimic Acid and Dithiocarbamic Acid The reaction between hydroxylamine, carbon disulfide, and alkyl halide leads to the corresponding ester of N-hydroxy dithiocarbimic acid HO? N?C(SR)₂ with R = CH₃, C₂H₅; R₂ = ? CH₂? CH₂? . The phenyl ester of N-hydroxy dithiocarbamic acid HO? NH? CS(SC₆H₅) has been prepared by reaction of hydroxylammonium chloride with the phenyl ester of chlorodithioformic acid. N-Methyl hydroxylammonium chloride reacts with carbon disulfide and alkyl iodide to form the corresponding ester of the dithiocarbamic acid HO? N(CH₃)? CS(SR) with R = CH₃, C₂H₅. The unstable compounds have been characterized by different methods.     

Über Chalkogenolate. LVIII. Untersuchungen über Thiomeiensäuren 6. Cyandithioameisensäure und Azidodithioameisensäure

Polymeric cyanodithioformic acid has been prepared by interaction between a solution of Na[NCCS₂]. 3 DMF and HCl(aq). In the gaseous state there exists [NCCS(SH)]_x with x = 1 and 2. The instable crystalline acidodithioformic acid is formed on reaction of Na[N₃CS₂] with HCl(aq). In the gaseous state there exists the monomeric acid N₃CS(SH).     

Herstellung von erythro-2-Hydroxybernsteinsäure-Derivaten aus Äpfelsäureester. Vorläufige Mitteilung

Preparation for erythro-2-Hydroxy-succinic Acid Derivatives from Malic Esters As a contribution to the much discussed diastereoselective synthesis of enantiomers of open chain compounds, > 90% erythro-selective branching of malic esters by alkylation of the doubly deprotonated derivative 2 (alkoxide-enolate) with methyl, allyl, and benzyl halides in THF at ?78° (→ 3aa, 3ba, 3bb, 3bc , Table 1) is described. A second alkylation (→ 4 ) and addition of 2 to acetone (→ 5 ) are also possible. Cyclization of 2 to the enantiomerically pure trans-epoxides 6 is achieved by treatment with iodine. Cuprate opening of 6b furnishes the same product 3ba obtained from the methylation of 2b , establishing the configurational assignment.     

Über Chalkogenolate. 133. Untersuchungen über Ester von Halogenoameisensäuren 1. Chloroameisensäure-, Chloromonothioameisensäure- und Chlorodithioameisensäurealkylester

On Chalcogenolates. 133. Studies on Esters of Haloformic Acids. 1. Alkyl Esters of Chloroformic, Chloromonothioformic, and Chlorodithioformic Acids The prepared esters RO? CO? Cl, RS? CO? Cl, RO? CS? Cl, and RS? CS? Cl with R = alkyl have been characterized by means of electron absorption, infrared, nuclear magnetic resonance, and mass spectra.     

Beiträge zur Viskosität geschmolzener Salze. II. Die Viskosität geschmolzener Aluininiumhalogenide

On the viscosity of molten salts. II. The viscosity of molten aluminium halides The datas of viscosity of molten aluminium chloride, bromide, and iodide determined by means of the hollow-body torsion method are described and discussed in connexion with the equations of ANDRADE and BATSCHINSKI. The datas for the bromide and iodide are in good agreement with the experience and the theory of molecular melts. The aluminium chloride shows deviations in several facts.     

Über Oberflächenverbindungen von Übergangsmetallen. V. Oligomere Reaktionsprodukte bei der Polyäthylen- Synthese mit Chrom-Oberflächenverbindungen

On surface compounds of transition metals. V. Oligomeric reaction products by the polymerization of ethylene with chromium surface compounds Short time polymerization of ethylene with Cr(II) and Cr(VI) surface species on oxide carriers produces oligomeric reaction products, when followed by protonolysis, that originate, at least in part, from the decomposition of a soluble organochromium complex. Different homologous series result according to the type of heterogeneous catalyst employed: with Cr(II) contact α-olefines are obtained (in presence of O₂ the corresponding n-aldehydes are formed), Cr(VI) contacts give straightchain methylketones. Whereas the aldehyde formation occurs in secondary reactions the CH₃CO endgroup is produced evidently through the primary oxidation of C₂H₄ with surface Cr(VI). A polymerization sequence is then discussed in terms of protonolysis products wherein the alkene and acetyl endgroups are attached at that chain end which is not bound to chromium.     

Beiträge zur Chemie des Schwefels. 108. Schmelzwärme und spezifische Wärme des flüssigen Schwefels. Einfluß von Verunreinigungen

Using an adiabatic calorimeter, the heat of transition S_α ? S_β, the heat of fusion of S_β and the specific heat of the liquid had been determined on sulfur samples refined by zone melting and samples doped with chlorine, bromine and iodine. The data obtained from pure sulfur (heat of fusion: 1608 ± 8 J/Tom, specific heat of the liquid at 120°C: 29,4 J/Tom.°C) are about 10% lower than comparable values of other authors. Apparently they represent heat of fusion and specific heat of the pure cyclooctasulfur. The measurements on doped samples (δH_S = 1736 ± 10 J/Tom) are in agreement with the data reported in literature and include a portion of enthalpy from the transition reaction of cycloocta-sulfur (S_λ) to catenaocta-sulfur (S_π), requiring extremly long equilibrium times in pure sulfur. The influence of impurity on the caloric properties of the liquid sulfur is also indicated by the increasing width and decreasing highness of the C_p-maximum at 159°C with increasing amount of halogens. For the heat of transition S_α → S_β, independent of the amount of impurity, the literature data could be confirmed. At the samples doped with iodine there was observed a previously unreported transition near 65,9°C.     

Über Chalkogenolate. 122. Untersuchungen über N-Cyanomonothiocarbimidsäure 2. Kalium-S-methyl-N-cyanomonothiocarbimat und S-Methyl-N-cyanomonothiocarbimidsäure

On Chalcogenolates. 122. Studies on N-Cyanomonothiocarbimic Acid. 2. Potassium S-Methyl N-Cyanomonothiocarbimate and S-Methyl N-Cyanomonothiocarbimic Acid The reaction of K₂[SOC?N? CN] · H₂O with H₃CI gives K[O(H₃CS)C?N? CN]. The potassium salt reacts with acid to form (HO)(H₃CS)C?N? CN and with H₃CO? CO? Cl to yield (H₃CO? CO? O)(H₃CS)C?N? CN. The compounds have been characterized by means of spectroscopic methods.     

Untersuchungen an Metallkatalysatoren. XVII. Phasenaufbau,Dispersität und Dehydrieraktivität Molybdän- und wolframmodifizierter Palladiumkatalysatoren

Investigations on Metal Catalysts. XVII. Phase Structure, Dispersity, and Dehydrogenation Activity of Palladium Catalysts Modifided by Molybdenum and Tungsten Molybdenum and tungsten containing palladium catalysts were prepared by reduction of mixtures from Pd(NO₃)₂ with MoO₃ and WO₃, respectively, with hydrogen at 600°C and 800°C. The powders were characterized by means of several methods: Determination of the oxidation state for molybdenum and tungsten, X-ray measurements, N₂ adsorption, CO chemisorption, H₂ sorption, dehydrogenation of cyclohexane. The properties of the samples (heated at 600°C) are determined to a high degree by the co-existence of the palladium phase as well as the molybdenum and tungsten oxide, respectively, in the mean oxidation state +4. The after-reduction at 800°C leads to a great portion of metallic molybdenum and tungsten in the concerned catalysts. There are references that the treatment at 800°C in the presence of hydrogen causes for the Pd? Mo catalysts an increase of the palladium content in the surface of the crystallites.     

Über Chalkogenolate. 111. Untersuchungen über Perthiocyansäure. 4. Kristall- und Molekülstruktur von Dimethylperthiocyanat

On Chalcogenolates. 111. Studies on Perthiocyanic Acid. 4. Crystal and Molecular Structure of Dimethyl Perthiocyanate (CH₃)₂C₂N₂S₃ crystallizes with Z = 4 in the monoclinic space group P2₁/c with cell dimensions a = 7.661(4) Å, b = 11.675(5) Å, c = 9.549(5) Å, β = 116.7(3)·. The crystal and molecular structure has been determined from single X-ray data at 20°C and refined to a conventional R of 0.062. The structure consists of isolated 3,5-bis(methylmercapto)-1,2,4-thiadiazole molecules. The 1,2,4-thiadiazole ring is plane and stabilized by mesomerism.     

Chalkogenidgläser mit organischen Komponenten. II. Über Gläser der Zusammensetzung Selen-Arsen-Jod-Biphenylen

Chalcogenide Glasses with Organic Components, II. Glasses of the Selenium-Arsenic-Iodine-Biphenylene System New solids were prepared by melting suitable glasses of the system Se? As? I and of 4,4′-Bis(diiodoarsa)biphenyle, and cooling them subsequently. The transformation temperatures, densities, dc-conductivities, and i.r. spectra of the solids are reported. These solids exhibit chain-like structures. The biphenylene groups are connected with the inorganic matrix by arsenic-carbon bonds. The structure especially of the biphenylene units as wall as the conductivity behaviour is discussed.     

Untersuchungen an Nickel-Zeolith-Trägerkatalysatoren. I. Herstellung und Charakterisierung von Nickel-Zeolith-Trägerkatalysatoren

By means of cation exchange nickel zeolites of the types A, X and Y were prepared with different (0.5–12.5% of weight) nickel, contents. Nickel zeolites of the A type up to 14% exchange and zeolites of the X type up to 27% exchange do not show changes in structure. Nickel zeolite catalysts were prepared by reduction of the nickel zeolites with hydrogen. Analyses of nickel metal in these catalysts showed that only part of the nickel cations is reduced. By means of hydrogen chemisorption it could be proved that the metallic nickel does not exist in atomic dispersion and is deposited on the external surface as well as inside the pores.     

Kristallstrukturen von Säurehydraten und Oxoniumsalzen. VIII. Dihydrat und primäres Ammoniumsalz der Trimetaphosphimsäure

Crystal Structures of Acid Hydrates and Oxonium Salts. VIII. Dihydrate and Primary Ammonium Salt of Trimetaphosphimic Acid The dihydrate of the crystal structure of trimetaphosphimic acid, H₃(PO₂NH)₃ · 2H₂O, crystallizes in the monoclinic space group P2₁/c with four formula units in the unit cell (a = 7.022(1), b = 14.008(1), c = 9.353(2) Å, β = 93.34(2)°). The primary ammonium salt includes one molecule of methanol in its crystal structure, the orthorhombic space group Pbca contains eight formula units NH₄H₂(PO₂NH)₃ · CH₃OH in the unit cell (a = 15.025(3), b = 7.264(1), c = 19.252(1) Å). The crystal structures have been determined from three-dimensional X-ray diffraction data collected with an automatic single crystal diffractometer. Both rings of phosphorus and nitrogen atoms show boat conformation with the nitrogen atoms in the imido form. A similar pattern of bond lengths in both molecules and the disorder of one water-oxygen atom in the dihydrate indicate a partial proton transfer from the acid molecule to the water structure. In both structures the anion is linked to other anions by three hydrogen bonds N–H ?O, with an approximate length of 2.9 Å and two very short hydrogen bonds O–H ?O of approximate length 2.5 Å.     

Stoffwechselprodukte von Mikroorganismen. 139. Mitteilung. Synthesen in der Sideramin-Reihe: Rhodotorulasäure und Dimerumsäure

t-Butyl (E)-O-acetyl-Δ²-anhydromevalonate could be prepared. by a Reformatsky reaction of 4-acetoxybutan-2-one and t-butyl bromoacetate. Condensation of its activated derivatives with the diketopiperazine of N⁵-hydroxy-L -ornithine led to di-O-acetyl dimerumic acid, which could be transformed, by ammonolysis, to dimerumic acid, identical with the natural compound. The corresponding acetohydroxamic acid, prepared by acetylation of the diketopiperazine, was identical with natural rhodotorulic acid.     

Stabilitätskonstanten der Kupferkomplexe von Acetessigsäureamiden. I

The stability constants of the copper complexes of acetoacetdialkylamides and substituted acetoacetanilides have been determined by potentiometric pH-measurements. The variation of stability constants with phenyl substituents is interpreted.     

Über Chalkogenolate. LV. Untersuchungen über Thioameisensäuren. 3. Darstellung und Eigenschaften der Dithioameisensäure

Amorphous trimeric dithioformic acid has been prepared by interaction between an aqueous solution of K[HCS₂] and HCl(aq). After 1/2 – 1 minutes, the polymeric acid [ HCS(SH)]_X precipitates from a clear yellow solution of [HCS(SH)]₃ in N,N-dimethyl formamide or dimethyl sulfoxide. In solution (HCCl₃, H₂CCl₂), the existence of monomeric dithioformic acid has been verified. In the gaseous state [HCS(SH)]_n exists with n = 1, 2, 3. The dithioformic acid was investigated by different methods.     

Aminomethylierung von Thiophosphorsäuredialkylester-, Phosphon- bzw. Thiophosphonsäurealkylesteramiden,Phosphon- bzw. Thiophosphonsäurediamiden und Diphenylthiophosphinsäureamid

Aminomethylation of Phosphoro-, Phosphono-, Phosphinoamidoates and -amidothioates Dialkylphosphoroamidates, alkyl-phosphonoamidates and phosphonoamidothioates react with C₂H₅O? CH₂? NR₂ and HCOH/HNR₂, respectively, as like as a N-aminomethylation forming the corresponding derivatives of the general formula R₂P(X)? NR′? CH₂? NR″₂? R = alkoxy, alkyl, aryl; R′ = H, alkyl; X = O, S; R″ = alkyl, cycloalkyl —. Under the same conditions phosphonodiamidoates and phosphonodiamidothioates yield RP(X)-[NR′? CH₂? NR″₂]₂ or RP(X)? NHR′? (NR′? CH₂? NR″₂) only. These compounds are not formed by interactions of RP(X)(NR′? CH₂OH)₂ with sec. amines. The aminomethylation of (C₆H₅)₂P(S)NH₂ gives unexceptional [(C₆H₅)₂P(S)]₂N? CH₂? NR′₂. The i.r. and ¹H-n.m.r. data of the prepared compounds, which can't be distilled mostly, are discussed.     

Nucleotide. XIV. Substituierte β-Phenyläthyl-Gruppen. Neue Schutzgruppen für Oligonucleotid-Synthesen nach dem Phosphorsäuretriester-Verfahren

XIV. Substituted β-Phenyl-ethyl Groups. New Blocking Groups for Oligonucleotide Syntheses by the Phosphotriester Approach Various o- and p-substituted β-phenylethanols ( 2–10 ) have been synthesized and investigated as blocking groups in the phosphotriester approach. A large number of 5′-O-tritylated thymidine-3′-phosphotriesters ( 13–36 ) with two different phosphate protecting groups have been prepared, characterized, and studied according to their chemical stability and usefullness for oligonucleotide syntheses. The combination of a 5′-O-monomethoxytrityl- and a 3′-(2,5-dichlorophenyl, p-nitrophenylethyl)-phosphate function as in 18 turned out to possess optimal properties as a monomeric nucleotide building block due to the fact that these blocking groups can be quantitatively and selectively be removed without harming each other by trifluoroacetic acid in chloroform to 41 , by oximate to 42 , and by DBU to 43 . The base-catalyzed removal of the monosubstituted phenylethyl groups by DBU or DBN respectively as well as the disubstituted phenylethyl groups by triethylamine in aprotic solvents is a β-elimination process leading to phosphodiesters without attack on the P-center.