- N-(5-nitro-2-pyrrolidinylphenyl)trifluoro-acetamide
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The reaction of 2-fluoro-5-nitroaniline with pyrrolidine and triethylamine in DMF gives 2-pyrrolidinyl-5-nitroaniline, and subsequent treatment with trifluoroacetic acid and thionyl chloride in DMF results in the title compound, C12H12F3N3O3, the molecular structure of which, determined by X-ray crystallography, is described. In recent years, the interest in using organic crystals with a charge-transfer interaction via highly delocalized π-electron states (e.g. nitroanilines with donor and acceptor substituents in para positions) has increased considerably, since many of them have shown non-linear optical properties [Chemla & Zyss (1986). In Nonlinear Optical Properties of Organic Molecules and Crystals, Vols. 1 and 2. Orlando: Academic Press]. N-(5-Nitro-2-pyrrolidinylphenyl)trifluoro-acetamide (TPNB) is a donor-acceptor substituted benzene derivative and belongs to a family of compounds which produce high molecular non-linearity. TPNB shows a charge transfer (CT) between the para-disposed pyrrolidino donor and nitro acceptor groups.
- Yanes, Carlos,Torres, Manuel,Lopez-Rodriguez, Matias,Nunez, Pedro,Brito, Ivan
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Read Online
- Dicyclopentaheptalene (Azupyrene) Chemistry. Electrophilic Monosubstitution. Theory and Experiment
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MNDO calculations were used to estimate the ground-state geometry, atom electron densities, heat of formation, ionization potential, gas-phase ΔH values for protonation, and ΔH and Ea values for electrophilic trifluoroacetylation and nitration with protonated trifluoroacetc anhydride and trifluoroacetyl nitrate, respectively, of azupyrene (1).The electron density at C-4 was greater than that at C-1, and C-3 was electron-deficient.Relative ΔH values predicted C-1 to be more reactive than C-4 in each case.Relative Ea values predicted C-1 to be more reactive to protonated trifluoroacetic amhydride but C-4 to be more reactive to protonated trifluoroacetyl nitrate.Experimentally, protonation of solid 1 with DClO4 showed a C-1:C-4 D incorporation ratio of ca. 2:1, and trifluoroacetylation gave mostly 1-substitution with trifluoroacetic achydride or trifluoroacetylpyridinium chloride.In contrast, nitration with trifluoroacetyl nitrate, 1-nitropyridinium fluoroborate, or nitronium fluoroborate gave very predominantly 4-substitution.
- Anderson, Arthur G. Jr.,Davidson, Ernest R.,Daugs, Edward D.,Kao, L. Glenn,Lindquist, Richard L.,Quenemoen, Kristine A.
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Read Online
- The Preparation and Some Reactions of 2,5-Dichloro-1,1,1,6,6,6-hexafluoro-3,4-diazahexa-2,4-diene
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The title azine(I) can be conveniently prepared by treatment of 1,2-bistrifluoroacetylhydrazine with NN-dimethylaniline hydrochloride in phosphoryl chloride at ca. 100 deg C.It undergoes facile displacement of one or both chlorine atoms on treatment with a variety of nitrogen-, oxygen- and sulphur-centred nucleophiles as well as with iodide and fluoride ions.The bisanilino-substituted azine (Vd) is thermally unstable and cyclises with elimination of aniline to the triazole (VIa), while the perfluoroazine (Vj) undergoes cycloaddition with acetylene.
- Barlow, Michael G.,Bell, David,O'Reilly, Neil J.,Tipping, Anthony E.
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Read Online
- Synthesis and Fungitoxic Evaluation of Acylamino-1,2,4-Triazoles
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Ten different acylamino-1,2,4-triazoles were prepared by the reaction of differently substituted benzoyl chlorides and acetyl chlorides with 4-amino-1,2,4-triazole using catalytic amount of triethylamine. The synthesized compounds were characterized using UV, 1H-nuclear magnetic resonance spectroscopy, and infrared spectroscopy. All the compounds were tested for their fungicidal potential against three fungal species, that is, Fusarium verticillioides, Macrophomina phaseolina, and Rhizoctonia solani using poisoned food technique. The synthesized compounds were tested at various concentrations along with standard carbendazim 50 WP. The amides synthesized by reaction of substituted benzoyl chlorides and 4-amino-1,2,4-triazole exhibited greater fungicidal activity against all the tested fungi as compared to the amides synthesized using substituted acetyl chlorides. Among all the tested compounds, 4-nitro-N-(4-H-1,2,4-triazol-4-yl)benzamide showed the maximum fungicidal activity with the least median effective dose (ED50) values of 100, 93, and 146 μg ml-1 against F verticillioides, M. phaseolina, and R. solani, respectively. All the compounds were found to be less effective than the standard used.
- Kaur, Gurinderjit,Kaur, Harleen,Kaur, Pardeep,Sharma, Sunita,Singh, Ravneet
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p. 389 - 395
(2021/11/22)
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- Copper-catalyzed three component C[sbnd]S/C[sbnd]N coupling for the synthesis of trifluorothioacetamides
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A copper-catalyzed three component C[sbnd]S/C[sbnd]N coupling reaction of imines with sulfur and CFC-113a was developed. The reaction involves amination and C[dbnd]S double bond formation of CFC-113a, leading to biologically important trifluorothioacetamides. The method features efficient construction of trifluorothioacetyl moiety from cheap sulfur and CFC-113a, and safe disposal for environmentally persistent Freon
- Hu, Bo-Lun,Song, Yi-Kang,Yao, Zengwen,Zhang, Guoqiang,Zhang, Xing-Guo
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supporting information
(2020/10/06)
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- Photooxidation preparation method of haloacetyl chloride
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The invention discloses a photooxidation preparation method of haloacetyl chloride. The halogenated alkane is mixed with an oxygen source and vaporized, and then the materials are introduced into a reactor for photooxidation to obtain haloacetyl chloride, the photooxidation reaction temperature is 5 to 60 DEG C, the stay time of the material is 1 to 50 s, and the molar ratio of the oxygen source to the halogenated alkane is 0.1 to 5:1, a quartz cold trap is arranged in the reactor, and the quartz cold trap is composed of a quartz inner shell and a quartz outer shell, a light source is arrangedin the quartz inner shell, and a double-layer cold trap jacket is formed between the quartz inner shell and the quartz outer shell, and the double-layer cold trap jacket is filled with circularly flowed filter liquid, and the filter liquid filters out ultraviolet light generated by the light source in a wavelength band of less than 300 nm. The method has the advantages of simple process, high yield, safety and environmental protection, and continuous operation.
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Paragraph 0022; 0025; 0034-0037
(2019/01/24)
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- Preparation method of trifluoroacetic acid
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The invention discloses a preparation method of trifluoroacetic acid. The preparation method comprises the following steps: (1), vaporizing 1,1,1-trifluoro-2-chloroethane and chlorine gas, then enabling the 1,1,1-trifluoro-2-chloroethane and chlorine gas to enter a fixed bed reactor with a catalyst, and performing a gas phase chlorination reaction to synthesize 1,1,1-trifluoro-2,2-dichloroethane;(2), vaporizing the 1,1,1-trifluoro-2,2-dichloroethane and oxygen, then performing an oxidation reaction under the action of a light source to obtain trifluoroacetyl chloride, condensing the unreacted1,1,1-trifluoro-2,2-dichloroethane, and then enabling the unreacted 1,1,1-trifluoro-2,2-dichloroethane to return to the reactor; (3), hydrolyzing the trifluoroacetyl chloride to obtain the trifluoroacetic acid. The preparation method has the advantages of a simple technology, high yield, few three wastes and the like; in addition, by the preparation method, the reaction conversion rate is high, the selectivity is high, the reaction production is continuous, and the safety and the environment friendliness are achieved.
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Paragraph 0025; 0026; 0028; 0029; 0031; 0032; 0034; 0035
(2019/01/16)
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- Design, synthesis and biological evaluation of Lenalidomide derivatives as tumor angiogenesis inhibitor
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Lenalidomide is a type of immunomodulatory agent with anti-tumor activity by mainly expressed in the anti-angiogenesis. In order to enhance the pharmacological activity of Lenalidomide, a series of Lenalidomide derivatives were designed as tumor angiogenesis inhibitors. The potential anti-angiogenesis targets of Lenalidomide derivatives were virtual screened on Auto-Dock 4.0 by using reverse docking method. The six target proteins, such as vascular endothelial growth factor receptor, epidermal growth factor receptor, fibroblast growth factor receptor, BCR-ABL tyrosine kinase, p38 mitogen activated protein kinase and metal protein kinase, were chosen as the targets. The Lenalidomide derivatives were synthesized by alkylated, acylated or sulfonylated Lenalidomide and verified by the 1H NMR, 13C NMR and LC–MS. Their anti-cancer activities were detected by using CCK-8 in the esophageal carcinoma cell line EC9706. The results indicate that the inhibitory activities of Lenalidomide derivatives were higher than that of Lenalidomide.
- Hu, Shengquan,Yuan, Libin,Yan, Hong,Li, Zhigang
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supporting information
p. 4075 - 4081
(2017/08/23)
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- METHOD FOR PRODUCING PEST CONTROLLING AGENT
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To supply a derivative having a 2-acyliminopyridine structure and being represented by the following formula (I) in an amount required as a pest control agent stably and at a low cost, provided is a method comprising the steps of: acylating an amino group at position 2 of a compound represented by formula (A) by use of an acylating agent, to thereby produce a compound represented by formula (B); and further alkylating a nitrogen atom at position 1 of the compound represented by formula (B): [where Ar represents a phenyl group or a 5-to 6-membered heterocycle, R1 represents a C1-6 alkyl group, and Y represents a hydrogen atom; a halogen atom; a hydroxyl group; a C1-6 alkyl group which may be substituted with a halogen atom; a C1-6 alkyloxy group which may be substituted with a halogen atom; a cyano group; a formyl group; or a nitro group].
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Paragraph 0106
(2014/07/09)
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- Atmospheric chemistry of t-CF3CHCHCl: Products and mechanisms of the gas-phase reactions with chlorine atoms and hydroxyl radicals
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FTIR-smog chamber techniques were used to study the products and mechanisms of the Cl atom and OH radical initiated oxidation of trans-3,3,3-trifluoro-1- chloro-propene, t-CF3CHCHCl, in 700 Torr of air or N 2/O2 diluent at 296 ± 2 K. The reactions of Cl atoms and OH radicals with t-CF3CHCHCl occur via addition to the CC double bond; chlorine atoms add 15 ± 5% at the terminal carbon and 85 ± 5% at the central carbon, OH radicals add approximately 40% at the terminal carbon and 60% at the central carbon. The major products in the Cl atom initiated oxidation of t-CF3CHCHCl were CF3CHClCHO and CF3C(O)CHCl2, minor products were CF3CHO, HCOCl and CF3COCl. The yields of CF3C(O)CHCl2, CF3CHClCOCl and CF3COCl increased at the expense of CF3CHO, HCOCl and CF3CHClCHO as the O2 partial pressure was increased over the range 10-700 Torr. Chemical activation plays a significant role in the fate of CF3CH(O)CHCl2 and CF 3CClHCHClO radicals. In addition to reaction with O2 to yield CF3COCl and HO2 the major competing fate of CF 3CHClO is Cl elimination to give CF3CHO (not C-C bond scission as previously thought). As part of this study k(Cl + CF 3C(O)CHCl2) = (2.3 ± 0.3) × 10-14 and k(Cl + CF3CHClCHO) = (7.5 ± 2.0) × 10-12 cm3 molecule-1 s-1 were determined using relative rate techniques. Reaction with OH radicals is the major atmospheric sink for t-CF3CHCHCl. Chlorine atom elimination giving the enol CF3CHCHOH appears to be the sole atmospheric fate of the CF 3CHCHClOH radicals. The yield of CF3COOH in the atmospheric oxidation of t-CF3CHCHCl will be negligible (3CHCHCl. the Owner Societies 2012.
- Andersen, M. P. Sulbaek,Nielsen,Hurley,Wallington
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experimental part
p. 1735 - 1748
(2012/04/23)
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- GASEOUS DIELECTRICS WITH LOW GLOBAL WARMING POTENTIALS
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A dielectric gaseous compound which exhibits the following properties: a boiling point in the range between about ?20° C. to about ?273° C.; non-ozone depleting; a GWP less than about 22,200; chemical stability, as measured by a negative standard enthalpy of formation (dHf0); a toxicity level such that when the dielectric gas leaks, the effective diluted concentration does not exceed its PEL; and a dielectric strength greater than air.
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- Bioisosteric replacement of the pyrazole 3-carboxamide moiety of rimonabant. A novel series of oxadiazoles as CB1 cannabinoid receptor antagonists
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Based on the bioisosteric replacement of the pyrazole C3-carboxamide of rimonabant with a 5-alkyl oxadiazole ring, a novel class of oxadiazole derivatives with promising biological activity towards CB1 receptors was discovered. Among them, compounds with an alkyl linker containing a strong electron-withdrawing group (e.g., CF3) and a sterically favorable bulky group (e.g., t-butyl) exhibited excellent CB1 antagonism and selectivity, and thus might serve as potential candidates for further development as anti-obesity agents.
- Chu, Cheng-Ming,Hung, Ming-Shiu,Hsieh, Min-Tsang,Kuo, Chun-Wei,Suja,Song, Jen-Shin,Chiu, Hua-Hao,Chao, Yu-Sheng,Shia, Kak-Shan
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experimental part
p. 3399 - 3407
(2009/02/05)
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- Method and apparatus for transforming chemical fluids using halogen or oxygen in a photo-treatment process
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A method of treatment of reactant fluids such as hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), hydrochlorocarbons (HCCs), and hydrocarbons (HCs) for the production of new chemical fluids. Another method of treatment for the transformation of the reactant fluids having impurities present in the chlorofluorocarbons (CFCs) or fluorocarbons (FCs) for yielding a high quality chemical product. Reactant fluids with impurities present in used CFC or FC may form an azeotropic mixture. A photochemical reaction is used wherein the reactant fluids are molecules with hydrogen atoms in a hydrogen-carbon bond. The process is comprised of the following steps: placing the reactant fluids into a process compartment of the photochemical reactor; placing halogen fluid or oxygen fluid into the process compartment of the photochemical reactor, wherein the halogen fluid is selected from a group consisting of chlorine (Cl2), bromine (Br2) and iodine (I2); and irradiating the fluids and the halogen or oxygen fluid using radiant energy from lamps operating in the visible and ultraviolet light regions of the electromagnetic spectrum to conduct thermolysis, photolysis and photochemical treatment by halogenating or oxidizing the molecules of the reactant fluids with the halogen or oxygen fluids to form halogenated or oxidized fluids during a dwell time period.
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Page/Page column 6-7
(2008/06/13)
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- Increasing the N-H acidity: Introduction of highly electronegative groups into the hydrazine molecule
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Various hydrazine derivatives containing combinations of trifluoroacetyl, trifluoromethanesulfonyl, and 2,4-dinitrophenyl groups were prepared. Synthetic strategy is studied in terms of using protecting groups and direct acylation. Georg Thieme Verlag Stuttgart.
- Bredikhin, Aleksei,T?ubrik, Olga,Sillard, Rannar,M?eorg, Uno
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p. 1939 - 1941
(2007/10/03)
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- Trifluoromethyl chloroformate, CIC(O)OCF3: Structure, conformation, and vibrational analysis studied by experimental and theoretical methods
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The gas phase conformational properties and geometric structure of trifluoromethyl chloroformate, CIC(O)-OCF3, have been studied by vibrational spectroscopy (IR (gas), IR (matrix), and Raman (liquid)), gas electron diffraction (GED), and quantum chemical calculation (HF, B3LYP and MP2 methods with 6-311G* basis sets). The molecule exhibits only one form having Cs symmetry with synperiplanar orientation of the O-C single bond relative to the C=O double bond. If heated Ar:CIC(O)OCF3 mixtures are deposited as a matrix at 14 K, bands appear in the IR spectra which are assigned to the anti form. At room temperature, the contribution of the anti rotamer is estimated to be less than 1%. This high energy conformer is not observed in the GED experiment. The structure of solid CIC(O)OCF3 was determined by X-ray diffraction analysis from crystals obtained at low temperature, using a miniature zone melting procedure. The molecule crystallizes forming a dimeric structure belonging to the monoclinic crystal system and adopts the P21/n spatial group. Furthermore, we report the structure of the similar molecule trifluoroacetyl chloride. CF3C(O)Cl, in its crystalline phase by using the same method.
- Erben, Mauricio F.,Della Vedova, Carlos O.,Boese, Roland,Willner, Helge,Oberhammer, Heinz
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p. 699 - 706
(2007/10/03)
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- Synthesis and properties of β-ethoxyvinyl polyfluoroalkyl ketones
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A number of β-ethoxyvinyl polyfluoroalkyl ketones were synthesized by acylation of ethyl vinyl ether with acid chlorides containing polyfluoroalkyl groups of different composition and structure. Some typical nucleophilic reactions of the title compounds with amines were carried out. Two new fluoro-containing pyrimidinoles were synthesized by the reaction of β- ethoxyvinyl polyfluoroalkyl ketones with urea.
- Gorbunova, Marine G.,Gerus, Igor I.,Kukhar, Valery P.
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p. 738 - 742
(2007/10/03)
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- Process for preparing polyfluorocarboxylic acid chlorides and perfluorocarboxylic acid chlorides
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A process for preparing compounds corresponding to the formula RCFXC(O)Cl, in which X is fluorine or chlorine and R is fluorine or a perfluorinated C1- C10-alkyl group, preferably chlorodifluoroacetyl chloride, by photochemical oxidation of R122 (CF2 ClCHCl2) and the preparation of trifluoroacetyl chloride by photochemical oxidation of R123 (CF3 CHCl2) with oxygen under irradiation. The reaction is preferably carried out without pressurization and without addition of elemental chlorine.
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- Production of carboxylic acid halides and carboxylate salts
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A process for preparing carboxylic acid halides and carboxylate salts by reacting metal or "onium" halides with carboxylic anhydrides, which process is very suitable for working-up anhydrous, spent catalyst preparations. The resulting carboxylic acid halide or carboxylate salt can be used as an acylating reagent or alkylating reagent, and metal halide or "onium" halide liberated during this can be reacted anew with carboxylic anhydride and regenerated, thereby making it possible to effect a hydrolysis-free alkylation or acylation without forming salt-type waste products. If the mixture of carboxylic acid halide and carboxylate salt is allowed to react with an alcohol, preferably in situ, the resulting ester can be isolated without hydrolysis.
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- Process for preparing polyfluorochlorocarbonyl chlorides and perfluorocarbonyl chlorides with addition of chlorine
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A process for preparing polyfluorochloro- and perfluorocarbonyl chlorides, for example for preparing perfluoropropionyl chloride, chlorodifluoroacetyl chloride or trifluoroacetyl chloride, in which starting materials are employed which have a CHCl2 group which is converted to a C(O)Cl group by photochemical oxidation with oxygen in the presence of added elemental chlorine and under exposure to activating irradiation by light having a wavelength λ≥290 nm. The procedure is preferably unpressurized. Outstanding conversions with high selectivity are achieved using doped Hg light sources.
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- Phosphoric-Carboxylic Anhydrides. New Synthetic Procedures and Reactions with Nucleophiles. Reexamination of the Reaction of Se-alkyl-phosphoroselenoates with Alcohols and Mercuric Trifluoroacetate
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Phosphorus trimethylsilyl esters RR'P(O)OSiMe3 react smoothly with carboxylic anhydrides to give phosphoric-carboxylic anhydrides RR'P(O)-O-COR" in excellent yield.A similar reaction proceeds between stannyl esters RR'P(O)OSnMe3 and carboxylic anhydrides.We also have found that the anhydrides RR'P(O)-O-COCF3 are formed in almost quantitative yield when the phosphorus acid halides RR'P(O)X (X=Cl,Br,I) are allowed to react with trifluoroacetic anhydride in the presence of N-methylimidazole. We were able to confirm again that acyclic phosphoric-carboxylic anhydrides exhibit acetylating properties towards amines and alcohols.Our findings contradict with those of Wozniak, Krzyzanowska and Stec relating to the reaction of Se-alkylphosphoroselenoates RR'P(O)SeR" with mercuric trifluoroacetate Hg(OCOCF3)2.Our interpretation of this reaction differs entirely from those presented by the above mentioned authors. Key words: phosphorus-carboxylic anhydrides, Se-alkyl-phosphoroselenoates
- Wasiak, J.,Helinski, J.,Dabkowski, W.,Skrzypczynski, Z.,Michalski, J.
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p. 1027 - 1032
(2007/10/02)
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- Atmospheric Chemistry of HCFC-133a: The UV Absorption Spectra of CF3CClH and CF3CClHO2 Radicals, Reactions of CF3CClHO2 with NO and NO2, and Fate of CF3CClHO Radicals
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The UV absorption spectra of CF3CClH and CF3CClHO2 radicals have been investigated.The CF3CClH spectrum was quantified over the wavelenght range 225-280 nm.The absorption cross section at 250 nm was (139+/-16)*10-20 cm2 molecule-1.The absorption spectrum for CF3CClHO2 was quantified over the wavelength range 225-290 nm, and at 250 nm ?250nm=(258+/-30)*10-20 cm2 molecule-1.The kinetics of the reactions of the peroxy radical CF3CClHO2 with NO and NO2 were studied and the derived rate constants were k3=(1.0+/-0.3)*10-11 cm3 molecule-1 s-1 and k4=(6.4+/-1.5)*10-12 cm3 molecule-1 s-1, respectively.The self-reaction rate for the CF3CClHO2 radicals were measured and a value of k6obs=(4.4+/-0.3)*10-12 cm3 molecule-1 s-1 was obtained.The reactions of F atoms with CF3CH2Cl and of CF3CClH with O2 were found to proceed with rate constants of k8=(2.0+/-0.6)*10-12 cm3 molecule-1 s-1 and k2=(1.4+/-0.1)*10-12 cm3 molecule-1 s-1, respectively.The reaction of CF3CClHO2 radicals with NO gives NO2, and by implication CF3CClHO radicals, which in the atmosphere (a) react with O2 to give CF3C(O)Cl and (b) decompse to give, most likely, CF3 radicals and HC(O)Cl.In 700 Torr of N2 diluent the rate constant ratio kO2/Kdiss=(2.1+/-0.4)*10-19 cm3 molecule-1.As part of the present work, relative rate techniques were used to measure rate constants for the reactions of Cl and F atoms with CF3CH2Cl of (6.8+/-1.2)*10-15 and (2.1+/-0.5)*10-12 cm3 molecule-1 s-1, respectively.All experiments were performed at 296+/-2 K.
- Moegelberg, Trine E.,Nielsen, Ole J.,Sehested, Jens,Wallington, Timothy J.
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p. 13437 - 13444
(2007/10/02)
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- Tropospheric degradation chemistry of HCFC-123 (CF3CHCl2): A proposed replacement chlorofluorocarbon
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HCFC-123 has been proposed as a replacement for some of the fully halogenated chlorofluorocarbons and other chlorinated hydrocarbons, which are being phased out under the Montreal Protocol. This paper reports laboratory studies which were undertaken to determine kinetic and mechanistic parameters of reactions involved in the atmospheric degradation of HCFC-123 and the use of these parameters in a 2D global model of the troposphere to evaluate the yields of products formed in the degradation. The experimental studies have made use of the laser flash photolysis technique with time-resolved ultra-violet absorption spectroscopy for the kinetic measurements and broad-band ultra-violet absorption spectroscopy for product characterization. Rate coefficients have been determined for the self-reaction of CF3CCl2O2 as (3.6 ± 0.5) x 10-12 cm3 mol-1 s-1 and for its reactions with HO2 and NO as (1.9 ± 0.7) x 10-12 cm3 mol-1 s-1 and (1.5-2.0) x 10-11 cm3 mol-1 s-1, respectively, at room temperature. Kinetic data have also been obtained for the reaction of CF3CCl2O2 with C2H5O2 and two channels have been identified; CF3CCl2O2 + C2H5O2 → CF3CCl2O + C2H5O + O2 k = (9 (-5+9) x 10-13 cm3 mol-1 s-1 and CF3CCl2O2 + C2H5O2 → CF3CCl2OH + CH3CHO + O2, k = (3.6 ± 0.5) x 10-12 cm3 mol-1 s-1. Studies undertaken using the Cl-initiated oxidation of HCFC-123 suggest that trifluoroacetyl chloride, CF3COCl, is the major product of the gas-phase degradation. The kinetic and mechanistic data have been used to formulate a chemical module of the degradation of HCFC-123 in the troposphere. The module has been incorporated into a 2D model of the global troposphere so that the potential atmospheric impact of using HCFC-123 can be assessed. HCFC-123 has been proposed as a replacement for some of the fully halogenated chlorofluorocarbons and other chlorinated hydrocarbons, which are being phased out under the Montreal Protocol. This paper reports laboratory studies which were undertaken to determine kinetic and mechanistic parameters of reactions involved in the atmospheric degradation of HCFC-123 and the use of these parameters in a 2D global model of the troposphere to evaluate the yields of products formed in the degradation. The experimental studies have made use of the laser flash photolysis technique with time-resolved ultra-violet absorption spectroscopy for the kinetic measurements and broad-band ultra-violet absorption spectroscopy for product characterization. Rate coefficients have been determined for the self-reaction of CF3CCl2O2 as (3.6±0.5)×10-12 cm3 mol-1 s-1 and for its reactions with HO2 and NO as (1.9±0.7)×10-12 cm3 mol-1 s-1 and (1.5-2.0)×10-11 cm3 mol-1 s-1, respectively, at room temperature. Kinetic data have also been obtained for the reaction of CF3CCl2O2 with C2H5O2 and two channels have been identified; CF3CCl2O2+C2H5O2→CF3CCl$ -2$/O+C2 H5O+O2, k = (9-5+9)×10-13 cm3 mol-1 s-1 and CF3CCl2O2+C2H5O2→CF3CCl$ -2$/OH+CH3 CHO+O2, k = (3.6±0.5)×10-12 cm3 mol-1 s-1. Studies undertaken using the Cl-initiated oxidation of HCFC-123 suggest that trifluoroacetyl chloride, CF3COCl, is the major product of the gas-phase degradation. The kinetic and mechanistic data have been used to formulate a chemical module of the degradation of HCFC-123 in the troposphere. The module has been incorporated into a 2D model of the global troposphere so that the potential atmospheric impact of using HCFC-123 can be assessed.
- Hayman,Jenkin,Murrells,Johnson
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p. 421 - 437
(2007/10/03)
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- Secondary and Tertiary 2-Methylbutyl Cations. 1. Trifluoroacetolysis of 2-Methyl-2-butyl Tosylate
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Trifluoroacetolysis rates for 3-methyl-2-butyl tosylate (4) and kinetic isotope effects at C(1) (kH/kD = 1.083 per H atom), C(2) (kH/kD = 1.10), and C(3) (kH/kD = 1.82) were determined.The products are 2-methyl-2-butyl trifluoroacetate (5, 98.5percent) and 3-methyl-2-butyl trifluoroacetate (6, 1.5percent).GC-MS analysis of products from labeled tosylates 4-1-d3 and 4-2-d showed that 42percent of the apparently unrearranged 6 had a methyl group shifted from the original C(3) to the original C(2), whereas 3.6percent methyl shift occurred in 5.The results do not substantiate a ks-kΔ competition mechanism.Instead, two carbocations, the tertiary 2-methyl-2-butyl (1) and the nominally secondary 3-methyl-2-butyl (2) intervene.The intimate structure of 2 is not established, but a symmetrical, methyl-bridged ion (3) does not agree with the results.A high β isotope effect does not require hydrogen assistance to ionization; ionization concerted with (assisted by) hydrogen migration is unimportant in formation of 1 (and 5) from 4.Instead, the reaction involves reversible formation of an intimate ion pair with subsequent rate-determining H shift (which for 2*OTs(-) is in competition with Me shift and ca. 25percent elimination) followed by solvent capture.Methyl migration in 2 may occur in the solvent-separated ion pair; alternatively, methyl or hydrogen migration is conformationally determined.At least 9percent of 1 is formed from 2 which has undergone methyl shift.Nucleophilic attack on 4 appears important only in strongly nucleophilic media like aqueous ethanol.The claim that nucleophilic solvent assistance is significant in solvolysis of other secondary alkyl substrates in TFA or 97percent hexafluoro-2-propanol is evaluated.Such a conclusion cannot be accepted on the basis of rate correlations alone, (i.e without product studies to support it).The implications of our results for the trifluoroacetolysis of 2-butyl tosylate are briefly discussed.
- Farcasiu, Dan,Marino, Gaye,Harris, J. Milton,Hovanes, Bruce A.,Hsu, Chang S.
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p. 154 - 162
(2007/10/02)
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- Photolysis of matrix-isolated perfluoroacetyl chloride, CF3C(O)Cl
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Perfluoroacetyl chloride is decomposed in an argon matrix to produce CF3Cl and CO.The compounds are identified when the bands of the initial IR spectra disappear with the concomitant appearance of signals at 1207, 1098, 782 and 562 cm-1, and the band 2137 cm-1 belonging to the CO stretching vibration of the CO molecule.This result is compared with related studies of similar compounds.
- Vedova, C. O. Della,Rubio, R. E.
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p. 279 - 282
(2007/10/02)
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- The Fluorosulfines XF2C(F)C=SO (X = F, Cl, Br), Their Synthesis and Unusual Type of Decomposition
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A new route for the synthesis of the sulfenyl chloride 3 opens an easy access to fluoro(trifluoromethyl)sulfine (6) by hydrolysis of 3, trapping 6 by Diels-Alder reaction with anthracene, and thermolysis of the formed compound 8.By addition of the thioacetyl fluorides XF2C(F)C=S (X=Cl,Br) to anthracene compounds 9a,b are obtained, which could be oxidized to the sulfene adducts 12a,b as well as to the sulfine adducts 13a,b.Thermolysis of the latter yields the sulfines 17a,b, which are unstable at room temperature.A second approach to 17a involves oxidation of 1,3-dithietane 11a to its S-oxide 14a (e.g. via an S,S-difluoro compound 15a) and subsequent thermolysis, but thermal decomposition predominates.An unusual decomposition has been observed for 17a,b which was hitherto unknown for sulfines. Key Words: Fluorosulfines / Fluorothione S-oxides / Diels-Alder-Adducts
- Gradel, Jan,Sundermeyer, Wolfgang
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p. 1889 - 1894
(2007/10/02)
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- A NEW EFFICIENT SYNTHESIS OF TRIFLUOROACETYL HALIDES AND MIXED ANHYDRIDES OF PHOSPHORUS AND TRIFLUOROACETIC ACIDS
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Reaction of trifluoroacetic anhydride with chloroanhydrides of phosphorus acids R2P(O)Cl results in formation of mixed anhydrides R2P(O)OCOCF3 and trifluoroacetic acid halides CF3COX (X=Cl, Br, I) in quantitative yield.
- Helinski, J.,Skrzypczynski, Z.,Wasiak, J.,Michalski, J.
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p. 225 - 226
(2007/10/02)
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- A Direct Preparation of Fluorinated Imides
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N-Fluorosulfuryltrifluoroacetimide and N-chlorosulfuryltrifluoroacetimide have been prepared in high yield by a one-step reaction of trifluorothiolacetic acid with the corresponding fluoro- and chlorosulfuryl isocyanates.The trifluoroacetimides are easily purified by vacuum sublimation from the crude product mixture.
- Folk, T. G.,Higgins, P. E.,Noftle, R. E.
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p. 433 - 435
(2007/10/02)
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- 4-hydroxy-3-quinolinecarboxamides with antiarthritic and analgesic activities
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A series of 4-hydroxy-3-quinolinecarboxamides has been synthesized and evaluated by the oral route as antiinflammatory agents in carrageenin-induced foot edema and adjuvant-induced arthritis and as analgesic agents in the acetic acid induced writhing test. Among the most active molecules, some have shown both analgesic and acute antiinflammatory activities. Others, such as compounds 24, 37, and 52, were only powerful peripherally acting analgesics. Compound 52, being active at 1 mg/kg (ED50), is the most potent compound in the series. Some analogues, substituted in the 2-position by an alcohol, ester, or amine function, displayed potent antiarthritic activity in the same range as that of piroxicam and were also active in acute tests of inflammation and nociception. They inhibited the activity of both cyclooxygenase and 5-lipoxygenase at micromolar concentrations. Compound 102 (RU 43526) showed potent antiarthritic activity (adjuvant-induced arthritis, ED50 = 0.7 mg/kg, po), and gastrointestinal tolerance (ED100 250 mg/kg, po) and thus it is presently undergoing an extensive pharmacological evaluation.
- Clemence,Le Martret,Delevallee,Benzoni,Jouanen,Jouquey,Mouren,Deraedt
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p. 1453 - 1462
(2007/10/02)
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- Process for preparing trifluoroacetyl chloride
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The invention relates to the preparation of trifluoroacetyl chloride by catalytic chlorination of trifluoroacetaldehyde with chlorine. Catalysis is performed in the vapor phase in a fixed bed or a fluidized bed reactor with an activated carbon catalyst. Optionally, hydrochloric acid and/or an inert diluent can be present with the reactant without affecting the results of this process.
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- A MODIFIED SYNTHESIS OF MOSHER'S ACID AND ITS USE IN A SENSITIVE STEREOISOMER ANALYSIS OF AMINO ACID DERIVATIVES
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A convenient and sensitive method for stereoisomer analysis of amino acid derivatives is described.It is based on the (19)F NMR-analysis of mixtures containing epimers of N-.-methoxy-.-trifluoromethyl-phenylacetyl alanine (MTPA).An improved procedure for the synthesis of MTPA is given.
- Hull, William E.,Seeholzer, Klaus,Baumeister, Marlies,Ugi, Ivar
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p. 547 - 552
(2007/10/02)
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- REGIOSPECIFIC PREPARATION OF α,α-DIHALOFLUOROMETHYL PERFLUOROALKYL KETONES.
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Acylation of F-phosphoranium salts with F-acyl chlorides gives the corresponding Z-perfluoro betaine in high yield.Subsequent chlorination or bromination regiospecifically yields the α,α-dihalofluoromethyl perfluoroalkyl ketones.
- Jeong, In Howa,Burton, Donald J.,Cox, Daryl G.
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p. 3709 - 3712
(2007/10/02)
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- SYNTHESE ET CARACTERISTIQUES SPECTRALES DE F-ALKYL-2-DIHYDRO-3,4 OXO-4 QUINAZOLINES
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In this paper we report the preparation of a series of 4(3H) quinazolinones substituted in the 2 position by a linear perfluoroalkyl-chain with RF as Cn F2n+1 (n=1,3,5,7).These compounds are obtained in two steps, action of F-acid chlorides on 2-aminobenzonitrile which affords the corresponding F-amides followed by cyclization of this intermediate with alkaline hydrogen peroxide.We isolated a reaction intermediate in the cyclization of N-(2-cyanophenyl)F-octanamide.All compounds were identified by the usual spectroscopic methods (IR, NMR 1H, 19F, mass spectrometry).
- Greiner, Jacques,Pastor, Raphael,Cambon, Aime
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p. 185 - 196
(2007/10/02)
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