- Synthesis, spectral properties, crystal structure and theoretical calculations of a new geminal diamine: 2,2,2-Trichloro-N,N?-bis(2-nitrophenyl)-ethane-1,1-diamine
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A new 2,2,2-trichloro-N,N?-bis(2-nitrophenyl)-ethane-1,1-diamine was synthesized by the reaction of 2-nitroaniline in DCM with the chloral formed by distillation of chloral hydrate over concentrated H2SO4. The structure of the title compound was identified by means of FT-IR, 1H NMR, and 13C NMR spectroscopic techniques. The crystal structure of the title compound has also been examined by using X-ray crystallographic techniques and found to be crystallized in the monoclinic crystal system and space group P21/n with the unit cell parameters: a = 7.7075(12) ?, b = 7.7396(10) ?, c = 28.247(4) ?, β = 93.602(5)°, V = 1681.7(4) ?3, Dx = 1.602 Mg m ? 3, and Z = 4 respectively. The calculated electronic structure properties of the title molecule such as HOMO-LUMO analysis, molecular electrostatic potential (MEP) map, and the Mulliken charge distributions were investigated by using the density functional theory (DFT) method. Theoretically calculated values exhibit the chemically hard, high kinetic stable and less reactive molecule.
- Ayd?n, Fatma,Arslan, N Burcu
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- Substituted nitrogen-bridged diazocines
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Novel nitrogen-bridged diazocines (triazocines) were synthesized that carry a formyl or an acetyl group at the CH2NR-bridge and bromo- or iodo-substituents at the distant phenyl ring. The photophysical properties were investigated in acetonitrile and water. As compared to previous approaches the yields of the intramolecular azo cyclizations were increased (from ≈40 to 60%) using an oxidative approach starting from the corresponding aniline precursors. The Z→E photoconversion yields in acetonitrile are 80–85% and the thermal half-lives of the metastable E configurations are 31–74 min. Particularly, the high photoconversion yields (≈70%) of the water-soluble diazocines are noteworthy, which makes them promising candidates for applications in photopharmacology. The halogen substituents allow further functionalization via cross-coupling reactions.
- Griebenow, Thomas,Herges, Rainer,Lentes, Pascal,Rudtke, Jeremy
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supporting information
p. 1503 - 1508
(2021/07/02)
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- Photocatalytic degradation of gaseous trichloroethylene on porous titanium dioxide pellets modified with copper(II) under visible light irradiation
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Porous titanium dioxide pellets modified with copper(II) ion (Cu-TiO2) were synthesized by sol-gel method with dialysis for photocatalytic degradation of gaseous trichloroethylene (TCE) under visible light (VL) irradiation. TCE was completely degraded by passing the gas stream (mole fractions of oxygen and TCE were 0.2 and 1.75 × 10?4, respectively) at the flow rate of 25 mL min?1 through 0.2 g of the Cu-TiO2 pellets (Cu content: 0.1 atom%) calcined at 200 °C. TCE was converted mainly to carbon dioxide, dichloroacetic acid (DCAA), and inorganic chlorine species. Relatively small quantities of pentachloroethane (PCA) and trichloroacetaldehyde (TCAH) were detected as products on the Cu-TiO2 surface. Comparison with porous TiO2 pellets under ultraviolet irradiation revealed that more chlorinated products and less carbon dioxide were formed on Cu-TiO2 under VL irradiation. The mineralization of TCE to carbon dioxide was calculated to be only ca. 30.0%. It is noted that DCAA, PCA and TCAH were accumulated on the surface and were extracted with ethyl acetate. The porous Cu-TiO2 pellets show promise as the photocatalyst acting under VL irradiation for converting TCE gas to chlorinated compounds which can be used in industries.
- Tashiro, Keigo,Tanimura, Toshifumi,Yamazaki, Suzuko
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p. 228 - 235
(2019/04/17)
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- Ciprofloxacin degradation in UV/chlorine advanced oxidation process: Influencing factors, mechanisms and degradation pathways
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Ciprofloxacin (CIP) is a widely used third generation fluoroquinolone antibiotics, and has been often detected in wastewater treatment plants. Finding an effective way to remove them from wastewater is of great concern. Ultraviolet (UV)/chlorine advanced oxidation process (AOP) has many advantages in micropollutant removal. In this study, CIP degradation in UV/chlorine process was investigated. Only 41.2% of CIP was degraded by UV photolysis and 30.5% by dark chlorination in 30 min, while 98.5% of CIP was degraded by UV/chlorine process in 9 min. HCO3 ? had markedly inhibition, NO3 ? and SO4 2- had slight inhibition, and Cl? had a marginal inhibition on CIP degradation in UV/chlorine system. The degradation of CIP in UV/chlorine process was mainly attributed to the attack of reactive species. The relative contributions of hydrated electrons (eaq [rad]), hydroxyl radicals (HO[rad]), chlorine atoms (Cl[rad]), and UV photolysis were investigated. Under neutral condition in aqueous solution, CIP degradation had highest pseudo first-order reaction rate constant, in which eaq [rad] had the highest contribution, followed by Cl[rad], HO[rad], and UV photolysis. The intermediates and byproducts were identified and the degradation pathway was proposed. The total organic chlorine (TOCl) and biotoxicity were further assessed. CIP and natural organic matters (NOMs) were removed efficiently in real water. UV/chlorine showed the potential for the wastewater treatment containing CIP.
- Deng, Jia,Wu, Guangxue,Yuan, Shoujun,Zhan, Xinmin,Wang, Wei,Hu, Zhen-Hu
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p. 151 - 158
(2018/11/24)
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- Asymmetric synthesis of propargylamines as amino acid surrogates in peptidomimetics
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The amide moiety of peptides can be replaced for example by a triazole moiety, which is considered to be bioisosteric. Therefore, the carbonyl moiety of an amino acid has to be replaced by an alkyne in order to provide a precursor of such peptidomimetics. As most amino acids have a chiral center at Cα, such amide bond surrogates need a chiral moiety. Here the asymmetric synthesis of a set of 24 N-sulfinyl propargylamines is presented. The condensation of various aldehydes with Ellman's chiral sulfinamide provides chiral N-sulfinylimines, which were reacted with (trimethylsilyl)ethynyllithium to afford diastereomerically pure N-sulfinyl propargylamines. Diverse functional groups present in the propargylic position resemble the side chain present at the Cα of amino acids. Whereas propargylamines with (cyclo)alkyl substituents can be prepared in a direct manner, residues with polar functional groups require suitable protective groups. The presence of particular functional groups in the side chain in some cases leads to remarkable side reactions of the alkyne moiety. Thus, electron-withdrawing substituents in the Cα-position facilitate a base induced rearrangement to α,β-unsaturated imines, while azide-substituted propargylamines form triazoles under surprisingly mild conditions. A panel of propargylamines bearing fluoro or chloro substituents, polar functional groups, or basic and acidic functional groups is accessible for the use as precursors of peptidomimetics.
- Wünsch, Matthias,Schr?der, David,Fr?hr, Tanja,Teichmann, Lisa,Hedwig, Sebastian,Janson, Nils,Belu, Clara,Simon, Jasmin,Heidemeyer, Shari,Holtkamp, Philipp,Rudlof, Jens,Klemme, Lennard,Hinzmann, Alessa,Neumann, Beate,Stammler, Hans-Georg,Sewald, Norbert
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supporting information
p. 2428 - 2441
(2017/12/06)
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- Liebeskind-Srogl cross-coupling on γ-carboxyl-γ-butyrolactone derivatives: Application to the side chain of amphidinolides C and F
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The synthetic approach for the C20-C29 and C20-C34 fragments of amphidinolide F and C was based on an original Liebeskind-Srogl cross-coupling reaction with a glutamic acid-derived building-block. Further highly diastereoselective reduction of the ketone was achieved by using an uncommon Ph3SiH/TBAF/HMPA system. The amphidinolide C side chain was built through a reductive elimination of chiral epoxide to install the stereogenic center at C29.
- Fenneteau, Johan,Vallerotto, Sara,Ferrié, Laurent,Figadère, Bruno
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supporting information
p. 3758 - 3761
(2015/06/08)
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- Facile stereoselective synthesis of 1,3-disubstituted-4-trichloromethyl azetidin-2-ones
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The highly stereoselective synthesis of 1,3-disubstituted-4-trichloromethyl azetidin-2-ones by the [2+2] cycloaddition of ketenes with imines derived from chloral is described. The highly stereoselective synthesis of 1,3-disubstituted-4-trichloromethyl azetidin-2-ones by the [2+2] cycloaddition of ketenes with imines derived from chloral is described.
- Govande,Deshmukh
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p. 6563 - 6566
(2007/10/03)
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- METHOD OF MAKING HYDROFLUOROCARBONS
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A method of producing hydrofluorocarbons and methods of producing other commercially attractive compounds formed as by-products of hydrofluorocarbon production by using aldehydes as a principal reactant.
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- Degradation pathways of trichloroethylene and 1,1,1-trichloroethane by Mycobacterium sp. TA27
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We analyzed the kinetics and metabolic pathways of trichloroethylene and 1,1,1-trichloroethane degradation by the ethane-utilizing Mycobacterium sp. TA27. The apparent Vmax and Km of trichloroethylene were 9.8 nmol min-1 m
- Hashimoto, Akiko,Iwasaki, Kazuhiro,Nakasugi, Naou,Nakajima, Mutsuyasu,Yagi, Osami
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p. 385 - 390
(2007/10/03)
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- Microsomal oxidation of tribromoethylene and reactions of tribromoethylene oxide.
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Halogenated olefins are of interest because of their widespread use in industry and their potential toxicity to humans. Epoxides are among the enzymatic oxidation products and have been studied in regard to their toxicity. Most of the attention has been given to chlorinated epoxides, and we have previously studied the reactions of the mono-, di-, tri-, and tetrachloroethylene oxides. To further test some hypotheses concerning the reactivity of these compounds, we prepared tribromoethylene (TBE) oxide and compared it to trichloroethylene (TCE) oxide and other chlorinated epoxides. TBE oxide reacted with H(2)O about 3 times faster than did TCE oxide. Several hydrolysis products of TBE oxide were the same as formed from TCE oxide, i.e., glyoxylic acid, CO, and HCO(2)H. Br(2)CHCO(2)H was formed from TBE oxide; the yield was higher than for Cl(2)CHCO(2)H formed in the hydrolysis of TCE oxide. The yield of tribromoacetaldehyde was 0.4% in aqueous buffer (pH 7.4). In rat liver microsomal incubations containing TBE and NADPH, Br(2)CHCO(2)H was a major product, and tribromoacetaldehyde was a minor product. These results are consistent with schemes previously developed for halogenated epoxides, with migration of bromine being more favorable than for chlorine. Reaction of TBE oxide with lysine yielded relatively more N-dihaloacetyllysine and less N-formyllysine than in the case of TCE oxide. This same pattern was observed in the products of the reaction of TBE oxide with the lysine residues in bovine serum albumin. We conclude that the proposed scheme of hydrolysis of halogenated epoxides follows the expected halide order and that this can be used to rationalize patterns of hydrolysis and reactivity of other halogenated epoxides.
- Yoshioka, Tadao,Krauser, Joel A,Guengerich, F Peter
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p. 1414 - 1420
(2007/10/03)
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- Acylation of protein lysines by trichloroethylene oxide
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Stable lysine adducts were formed in proteins following reaction with trichloroethylene (TCE) oxide, the major reactive compound generated by the metabolism of TCE. The order of formation of these adducts is N6- formyllysine > N6-(dichloroacetyl)lysine >> N6-glyoxyllysine, with the ratio being influenced by the particular protein. Protein lysine adducts were also analyzed following the enzymatic oxidation of TCE with several different cytochrome P450 (P450) enzyme systems. The ratio of formyl/dichloroacetyl lysine adducts was influenced by the enzyme system that was used. Chloral and TCE oxide formation was more extensive with rat liver microsomes isolated from phenobarbital-treated rats than with rat microsomes in which P450 2E1 was induced by treatment with isoniazid or in human P450 2E1 systems. Glutathione (GSH) and GSH transferase had inhibitory effects on the reaction of TCE oxide with albumin, with formylation being attenuated much more than the formation of dichloroacetyllysine. GSH is likely to react with the reactive acyl chloride intermediates formed from TCE oxide hydrolysis, instead of direct reaction with TCE oxide, as judged by the lack of an effect of GSH on the rate of decomposition of TCE oxide. Studies with the model enzymes aldolase and glucose-6-phosphate dehydrogenase, both known to have sensitive lysine groups, indicate that TCE oxide has effects similar to known acylating agents that form the same adducts; concentrations of TCE oxide (or the model acylating agents) in the low-millimolar range were needed for inhibition. The characterization of TCE-derived protein adducts can be used as a basis for consideration of the exposure and risk of TCE to humans. Human P450 2E1 was less likely to oxidize TCE to form TCE oxide and protein lysine adducts than rat P450 2B1, and the difference is rationalized in terms of the influence of the protein on chloride migration in an enzyme reaction intermediate.
- Cai, Hongliang,Guengerich, F. Peter
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p. 327 - 335
(2007/10/03)
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- Formic acid as a hydride donor: Reduction of acid chlorides to aldehydes
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Chlorides of a variety of acids: primary, secondary, tertiary, long chain aliphatic and αβ-unsaturated have been converted into aldehydes by reduction with formic acid at pH 9-10 at room temperature in high yields.
- Shamsuddin,Zobairi, Md. Omair,Musharraf, Mohd. Asif
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p. 8153 - 8154
(2007/10/03)
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- Process for the hydroxyalkylation of a carbocyclic aromatic ether
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The present invention concerns a process for the hydroxyalkylation of a carbocyclic aromatic ether. The invention preferably relates to the preparation of 3-methoxy-4-hydroxybenzyl alcohol by the hydroxymethylation of guaiacol. It also concerns the oxidation of the hydroxyalkylated ethers obtained, in particular the oxidation of 3-methoxy-4-hydroxybenzyl alcohol to 3-methoxy-4-hydroxybenzaldehyde, commonly known as "vanillin". The process for the hydroxyalkylation of a carbocyclic aromatic ether of the invention consists of reacting the aromatic ether with a carbonyl compound in the presence of a catalyst and is characterized in that the hydroxyalkylation reaction is carried out in the presence of an effective quantity of a zeolite.
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- High utility of Saccharomyces cerevisiae harboring rat liver cytochrome P450 1A2 cDNA in haloethanes dehalogenations
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Yeast harboring rat liver P450 1A2 efficiently degraded trichloroethylene, pentachloroethane and hexachloroethane. Since liver P450s catalyze degradation of thousands of chemicals, this method is promising for chemical-directed degradation of environmental pollutants.
- Yanagita, Kazutaka,Sagami, Ikuko,Shimizu, Toru
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p. 561 - 562
(2007/10/03)
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- Para-hydroxyalkylation of hydroxylated aromatic compounds
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Hydroxylated aromatic compounds devoid of substituents in the para-position to the hydroxyl group thereof are para-hydroxyalkylated, e.g., into optionally substituted p-hydroxymandelic acid compounds, more particularly p-hydroxymandelic acid and 3-methoxy-p-hydroxymandelic acid, by condensing same with an organic carbonyl compound in the presence of a quaternary ammonium hydroxide.
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- Preparation of dichloroacetaldehyde cyclic trimer and its depolymerization
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Dichlorination of paraldehyde followed by hydration gave white crystals of dichloroacetaldehyde(DCA) hydrate which were treated with concd sulfuric acid at 0°C to afford a cyclic trimer of DCA as a quite stable precursor of DCA.
- Wakasugi,Miyakawa,Suzuki,Itsuno,Ito
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p. 1289 - 1294
(2007/10/02)
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- A Theoretical and Experimental Investigation of Vicinal Tricarbonyl Systems and Their Hydrates
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The conformational preference of the vinyl vicinal tricarbonyl reagent (VTC) and related triketones have been examined in the context of ab initio molecular orbital theory in order to better understand the properties of these reactive polyelectrophiles.The preferred conformation of the VTC methyl ester has been calculated to have the glyoxal unit twisted almost perpendicular to the plane of the ester unit.These results support the recent conclusions of Schreiber and co-workers on the activity of FK-506 and related compounds for inhibition of the rotamase enzyme.The origin of the enhanced reactivity has been examined via an analysis of the charge density distribution of the triketones and the corresponding hydrates.Electrostatic stabilization appears to be the main driving force for the stability of the hydrates.The energy of hydration for VTC has been calculated to be similar to that of activated aldehydes such as fluoral and chloral.Experimental values are also presented for the energy of hydration of chloral and VTC in acetone solution.
- Henke, Susan L.,Hadad, Christopher M.,Morgan, Kathleen M.,Wiberg, Kenneth B.,Wasserman, Harry H.
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p. 2830 - 2839
(2007/10/02)
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- INSERTION REACTIONS IN THE P-Hal BOND IN PHOSPHORANES. SYNTHESIS OF 1(1-HALOALKOXYL)PHOSPHORANES
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Functionally substituted (1-haloalkoxy)phosphoranes were synthesized by the reactions of cyclic, bicyclic, and acyclic mono-, di-, and tri-halophosphoranes with chloral and bromal.
- Moronov, V. F.,Sinyashina, T. N.,Ofitserov, E. N.,Karataeva, F. Kh.,Chernov, P. P.,et al.
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p. 527 - 544
(2007/10/02)
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- LASER INDUCED GAS PHASE REACTION BETWEEN CHROMYL CHLORIDE AND SOME POLYHALOGENOETHENES
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Gas phase reaction between chromyl chloride and some polyhalogenoethenes induced with the radiation of continuous-wave CO2 laser yields carbonyl halides and compounds arising from oxygen donation to alkene and 1,2-rearrangement of halogen.
- Pola, Josef,Vitek, Josef
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p. 682 - 685
(2007/10/02)
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- Kinetics of Reactions of Hydroxyl Radicals with a Series of Aliphatic Aldehydes
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The kinetics of reactions of hydroxyl radical with acetaldehyde and its alkyl and halogen substituted derivatives has been investigated in the temperature range 298-520 K with the discharge flow/resonance fluorescence technique.The following reactions were studied and Arrhanius parameters were obtained (the preexponential factors are given in 1E12 cm3 mol-1 s-1, the activation energies in kJ mol-1 units): (1) OH + CF3CHO a = 7 (assumed) E = 5.9 (2) OH + CCl3CHO a = 7.1 +/- 1.5 E = 5.0 +/- 0.8 (3) OH + CH3CHO a = 5.2 +/- 1.1 E = -1.7 +/- 0.7 (4) OH + (CH3)2CHCHO a = 9.5 +/- 3.0 E = -2.6 +/- 1.2 (5) OH + (CH3)3CCHO A = 8 +/- 4 E = -3.4 +/- 1.7. - Key words: Chemical Kinetics / Elementary Reactions / Radicals
- Dobe, S.,Khachatryan, L. A.,Berces, T.
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p. 847 - 852
(2007/10/02)
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- Process for the preparation of fluoroformates
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A process for the preparation of fluoroformates of formula: STR1 in which R1 is a substituted or unsubstituted, saturated or unsaturated aliphatic, cycloaliphatic or polycyclic radical, or substituted or unsubstituted araliphatic radical or an aromatic radical, which consists of reacting a carbonate of formula: STR2 in which R1 has the same meaning as hereinabove and R2 is hydrogen, alkyl of 1-12 carbon atoms, cycloalkyl of 5-12 carbon atoms, saturated or unsaturated, unsubstituted or substituted by one or more halogen atoms or R2 is aryl, unsubstituted or substituted by one or more halogen atoms, with an alkali or alkaline earth fluoride, ammonium fluoride or a quaternary ammonium fluoride, of formula FNR3 R4 R5 R6, wherein R3, R4, R5, R6 are the same or different and are hydrogen, alkyl or aralkyl of 1-12 carbon atoms or a fluoride which is KHF2, NH4 HF2 or KSO2 F. The fluoride is activated by a complexing agent for the cation which is a cryptate, a cyclic or linear polyether or by means of a polar aprotic compound. The carbonate is split to give a reaction mixture containing an aldehyde and the fluoroformate which is removed from the reaction mixture.
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- 1,2,2,2-Tetrachloroethyl tert-Butyl Carbonate: A Simple and Efficient Reagent for the tert-Butoxycarbonylation of Amines and Amino Acids
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The reaction of 1-chloroalkyl carbonates with amines affords good yields of the corresponding carbamates.Application to the BOC protection of amino acids is described.
- Barcelo, Gerard,Senet, Jean-Pierre,Sennyey, Gerard
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p. 3951 - 3953
(2007/10/02)
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- BEITRAEGE ZUR CHEMIE DES IODPENTAFLUORIDS TEIL II. IOD(V)-VERBINDUNGEN MIT α,ω-DIFUNKTIONELLEN ALKOHOLATEN
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Nucleophilic subsitution reactions if iodine pentaflurode with a series of homologous bifunctional alcoholates -(CH2)nO- (n=2,3,4,5,6,12), a geminal dialcoholate CCl3CH(O-)2 and a trifunctional alcoholate CH3C(CH2O-)3 protected by (CH3)3Si - groups are reported.Systems with short CH2 - chains (nX (X = SiMe3, IF4) which rearrange to mononuclear chelates IF3 of high stability.Dialcoholates with long CH2-chains (n>4) behave as bridging ligands forming stable multinuclear compounds IF4IF4 and (IF3)m (m>2). 1,4-Butanediolate is on the border line of the two systems.Products with greater subsitution IF2 (n=2,3) and IF2(OCH2)3CCH3 are also characterized.The dependence of 19F-NMR-shifts on the nature and arrangement of ligands is discussed.
- Frohn, Hermann Josef,Pahlmann, Wolgang
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p. 243 - 256
(2007/10/02)
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- REACTIVITY OF CHLOROSUBSTITUTED α-EPOXIDES AND SYNTHESES UNDER THESE COMPOUNDS
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The reactivity of chloroepoxyethanes in reactions with nucleophiles and electrophiles increases sharply with the accumulation of chlorine atoms on the epoxide ring.The reaction rate correlates with the nucleophile strength.Reactions with strong nucleophiles proceed through epoxide isomerization and lead to chloroacetic acid derivatives.Addition to the epoxide ring is found only for several weak nucleophiles.
- Voronina, T. A.,Fomina, N. V.,Suminov, S. I.
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p. 1059 - 1063
(2007/10/02)
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- ISOMERIZATION OF CHLORINE-SUBSTITUTED α-OXIDES
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During the thermal and catalytic isomerization of chlorine-substituted epoxyethanes to the corresponding carbonyl compounds the reaction rate increases with increase in the number of chlorine atoms in the molecule.Active catalysts are amines, Lewis acids, and sulfuric acid but not hydrochloric acid and carboxylic acids) the type of catalyst (acid or base) affects the direction of isomerization in the unsymmetrical chloroepeoxyethanes.
- Voronina, T. A.,Chernyavskii, A. I.,Dobrov, I. V.,Poluektov, V. A.,Fomina, N. V.
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p. 801 - 805
(2007/10/02)
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- Nitrile Sulphide Formation from the Thermal Fragmentation of 1,3,4-Oxathiazoles: a Retro-1,3-dipolar Cycloaddition
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1,3,4-Oxathiazoles, on thermolysis, undergo retro-1,3-dipolar cycloaddition to afford carbonyl compounds and nitrile sulphides, which may be trapped by cycloaddition with alkynes and nitriles.
- Paton, R. Michael,Robertson, Fiona M.,Ross, John F.,Crosby, John
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p. 714 - 715
(2007/10/02)
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- Herbicidal semicarbazones
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2-Phenylsemicarbazones of the formula STR1 ARE USEFUL AS HERBICIDES. The 2-phenylsemicarbazones are prepared by reaction of a phenylhydrazone with a strong base followed by reaction with a carbamoyl chloride or an alkyl isocyanate.
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