- VIBRATIONAL SPECTRA AND ROTATIONAL ISOMERISM OF ETHYL TRICHLOROACETATE
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The IR and Raman spectra of ethyl trichloroacetate (E-TCA) and its deuterate (E-TCA-d5) have been measured in the liquid, glassy and crystalline states.Vibrational assignment was made by referring to isotopic wavenumber-shift, characteristic group frequencies of related esters and with the aid of a normal coordinate calculation on E-TCA and E-TCA-d5.It is suggested that in the liquid and glassy states there exist two molecular forms (trans-trans-trans and trans-trans-gauche) with regard to the internal rotations about the CIC-C-O-CH2CH3 axis, and that the former persists in the crystalline state.The band pairs of E-TCA and the other ethyl esters are discussed in relation to the nature and number of rotational axes, effect of the heavy trichloromethyl group, and enhancement of band intensity by vibrational coupling.
- Mido, Yoshiyuki,Kawashita, Tomoko,Suzuki, Kyoko,Morcillo, Jesus,Garcia, M. Victoria
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Read Online
- Alkyl Halides via Visible Light Mediated Dehalogenation
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Net selective bromination and chlorination of activated C-H bonds can be effected in generally high yield via a simple perhalogenation/dehalogenation sequence. The photochemical reductions require no photocatalyst, relying instead on the formation of an electron donor-acceptor complex of the substrate and reductant, or alternatively autophotocatalysis. Some reactions proceed despite any apparent photon absorption, serving as a cautionary tale for other photochemical reactions involving amines. Mechanistic experiments provide an explanation for this observation.
- Rathnayake, Manjula D.,Weaver, Jimmie D.
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supporting information
p. 9681 - 9687
(2019/11/28)
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- A method for the preparation of trichloroacetyl chloride with silicon tetrachloride (by machine translation)
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The invention discloses a method for the preparation of trichloroacetyl chloride with silicon tetrachloride, silicon tetrachloride used as acyl chloride reagent, and trichloro acetic acid in 60-70 °C reaction under 2-4 hours, generating acetic chloride, generated after the cure, the trichloro acetyl chloride and other products by distillation or extraction method for separating. The effective conversion of this invention and an organosilicon polycrystalline silicon production of by-product production in a large amount of silicon tetrachloride, trichlor-production with high added value; in the conversion treatment brought by the development of the production of polycrystalline silicon is difficult to control at the same time the by-product silicon tetrachloride, significantly reduces the cost of the preparation of trichloroacetyl chloride. (by machine translation)
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Paragraph 0037; 0038
(2016/11/17)
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- Efficient partial hydrogenation of trichloromethyl to gem-dichloromethyl groups in platinum on carbon-catalyzed system
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While gem-dichloromethyl groups can be directly synthesized by the mono-dechlorination of the corresponding trichloromethyl groups, the suppression control of the over-reduction to form chloromethyl or methyl functionalities is quite difficult. We have established the efficient and widely applicable mono-dechlorination method of the trichloromethyl groups to form the corresponding gem-dichloromethyl groups using platinum on carbon in dimethylacetamide as a specific solvent at 25 °C under a hydrogen atmosphere. The mono-dechlorination of the α,α,α- trichloromethylcarbonyl groups smoothly proceeded by the use of platinum on carbon as a catalyst in a highly chemoselective manner, while the efficient mono-dechlorination of the alkyl- and aryl-trichloromethyl groups required the combined use of Bu3SnH.
- Sawama, Yoshinari,Imanishi, Takahiro,Nakatani, Ryosuke,Fujiwara, Yuta,Monguchi, Yasunari,Sajiki, Hironao
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supporting information
p. 4540 - 4546
(2014/06/10)
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- Chlorinated promoters for vanadium-based polymerization catalysts
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Promoters are described for vanadium-based catalysts used in the (co)polymerization of olefins and, in particular, in the production of ethylene/propylene (EPR) or ethylene/propylene/diene (EPDM) elastomeric copolymers. The promoters of the present invention belong to the group of compounds having general formula I: wherein:"X" represents a (-CO-) carbonyl or (-SO2-) sulfonyl group;"n" is 0 or 1;R' is an alkyl or alkylaryl group having from 1 to 20 carbon atoms;R" = R', H.
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- Catalytic esterifications of carboxylic acids and alcohols by sodium bisulfate monohydrate
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The efficient esterification of primary and secondary alcohols with aliphatic carboxylic acids in the presence of a catalytic amount of sodium bisulfate monohydrate to afford the corresponding esters in high yields.
- Li, Yi-Qun
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p. 3901 - 3903
(2007/10/03)
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- Process for the reaction of a low-molecular hydroxyl compound with a carboxylic acid halide
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In a process for reacting a low molecular weight hydroxy compound with a carboxylic acid halide, a small amount of the acid halide is introduced into the reaction vessel and the remainder of the acid halide and the hydroxy compound are added gradually in an approximately stoichiometric ratio. The hydrogen halide formed is thus prevented from dissolving in the reaction medium. The heat of reaction to be dissipated is negligible.
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- REACTIONS OF CHLORINE MONOFLUORIDE. IV. ADDITION OF CHLORINE MONOFLUORIDE TO HALOGEN-SUBSTITUTED ALKENES
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The reactions of chlorine monofluoride with halogenoethylenes (1,1-dichloro-, 1,2-dichloro-, trichloro-, and tetrachloroethylenes) and halogenopropenes ( 3-bromo-, 3,3,3-trichloro-, E- and Z-1,3-dichloro-, 3-chloro-2-methyl-, and perfluoropropenes) were investigated in inert solvents in the presence of ethyl acetate as external nucleophile.In all cases chloroacyloxy adducts were isolated and identified in addition to the chlorofluorination products, and this indicates an electrophilic mechanism for the chlorofluorination of polyhalogenoalkenes.Methyl chloromaleate, chlorofumarate, chlorofluoroethylenedicarboxylate, α,β-difluoroacrylate, and perfluoromethacrylate in anhydrous hydrogen fluoride form the corresponding chlorofluoro adducts with satisfactory yields, whereas the reaction takes place with difficulty in inert solvents.
- Boguslavskaya, L. S.,Chuvatkin, N. N.,Panteleeva, I. Yu.
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p. 1832 - 1842
(2007/10/02)
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- A HIGH YIELD ROUTE TO ETHYL ESTERS OF CARBOXYLIC ACIDS
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Diethyl trichloromethylphosphonate reacts with carboxylic acids to yield their ethyl esters, via transesterification; even the hindered mesitoic acid is esterified in high yield.
- Downie, Ian M.,Wynne, Neil,Harrison, Stephen
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p. 1457 - 1458
(2007/10/02)
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- Treatment of ulcers with acylated aminoalkyl cyanoguanidines containing a heterocyclic residue
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There are prepared compounds corresponding to the formula STR1 in which X is a 5-membered or 6-membered aromatic heterocyclic radical which is attached through a carbon atom to the adjacent CH2 -group and which contains from 1 to 3 nitrogen atoms or one nitrogen atom and one oxygen or sulphur atom, and which may be substituted once or twice by substituents defined hereinbelow, each R1 represents hydrogen or a C1 -C4 -alkyl group, Alk represents a C2 -C6 -alkylene chain and Ac is defined hereinbelow and their salts.
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- Neutral Trichloroacetylations of Alcohols by Hexachloroacetone
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The addition of simple alcohols in hexachloroacetone (HCA) in the presence of strong hydrogen bond acceptors (e.g., dimethylformamide) results in a high yield of the corresponding trichloroacetate (via a haloform reaction scheme).The trichloroacetylation reactions are carried out under neutral conditions, and the resultant ester can easily be separated from the reaction mixture via extraction/distillation procedures.Kinetic evidence demonstrates that the trichloroacetylation of alcohols by HCA is a stereoselective process, and further studies suggest that the catalytic role of the acceptors is of a hydrogen bonding nature.
- Freedlander, Richard S.,Bryson, Thomas A.,Dunlap, R. Bruce,Schulman, E. M.,Lewis, Charles A.
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p. 3519 - 3521
(2007/10/02)
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