- Thermal degradation processes in polysulphide polymers investigated by flash pyrolysis gas chromatography/mass spectrometry
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Thermal degradation of four polysulphides, poly(methylenesulphide), poly(methylenedisulphide), poly(methylenetetrasulphide), and poly(styrenesulphide)-co-poly(methylenesulphide) have been investigated by pyrolysis gas chromatography/mass spectrometry technique (Py-GC/MS). The pyrolysis products detected by Py-GC/MS indicate that the thermal decomposition of these polymers yields cyclic sulphides by an intramolecular exchange process. The linear products with thiol end groups also form along with the cyclic products through a β-CH hydrogen transfer reaction.
- Sundarrajan, Subramanian,Ganesh, Kannan,Kishore, Kaushal,Surianarayanan, Mahadevan
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p. 491 - 496
(2007/10/03)
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- Flash vacuum pyrolysis of stabilised phosphorus ylides. Part 15. Generation of alkoxycarbonyl(sulfenyl)carbenes and their intramolecular insertion to give alkenyl sulfides
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A range of 18 alkoxycarbonyl sulfinyl phosphorus ylides 9 have been prepared and their behaviour upon flash vacuum pyrolysis (FVP) at 600 deg C examined. For R1 = H, Me and Et they lose Ph3PO and in some cases Ph3P to give mixtures of products including the alkenyl sulfides 10, the sulfides 11, the disulfides 12 and the thioesters 14. The alkenyl sulfides 10 most likely arise from intramolecular insertion of the alkoxycarbonyl sulfenyl carbenes resulting from loss off Ph3PO to produce β-lactones which then lose CO2 and this is supported by the results from 13C labelled ylides. Possible mechanisms for the formation of 11 and 14 are also presented and the feasibility of various steps has been examined by preparation and pyrolysis of the proposed intermediates. In contrast, pyrolysis of the ylides 9 where R1 = Ph and the tert-butoxycarbonyl ylides 30 leads mainly to complete fragmentation with loss of Ph3PO and benzyl alcohol or 2-methylpropan-2-ol and does not give any useful sulfur-containing products. Four alkoxy-carbonyl sulfonyl diazo compounds 33 have been prepared and in three cases they give the alkenyl sulfones 34 upon FVP at 400 deg C, probably by an intramolecular insertion and decarboxylation process analogous to the formation of 10 from 9. On the other hand the alkoxycarbonyl carbenes produced by FVP of the amino acid-derived diazo compounds 35 undergo alternative proocesses with no sign of β-lactone formation. Fully assigned 13C NMR data are presented for 13 of the ylides.
- Aitken, R. Alan,Armstrong, Jill M.,Drysdale, Martin J.,Ross, Fiona C.,Ryan, Bruce M.
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p. 593 - 604
(2007/10/03)
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- HIGH-TEMPERATURE ORGANIC SYNTHESIS. XXVI. REACTIONS OF ALKANETHIOLS AND DIALKYL SULFIDES AND DISULFIDES WITH VINYL CHLORIDE
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An abnormal directions was established in the thermal reactions of alkanethiols and dialkyl sulfides and disulfides with vinyl chloride, leading to the formation of the corresponding 1,1-bis(alkylthio)ethanes.
- Kuznetsova, M. A.,Deryagina, E. N.,Voronkov, M. G.
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p. 2130 - 2132
(2007/10/02)
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- DIVINYL SULFIDE. XIV. DIVINYL SULFIDE AND SULFUR-CONTAINING HETEROCYCLES FROM VINYL HALIDES AND SODIUM SULFIDE
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The reaction of vinyl halides with hydrated sodium sulfide in the potassium hydroxide-DMSO (HMDTA) superbasic system leads to the formation of divinyl sulfide, 2,5-dimethyl-4-methylene-1,3-oxathiolane, 2,4,5-trimethyl-1,3-oxathiole, and 2-thiabicyclohept-3-ene and also dimethyl sulfide, vinyl methyl sulfide, and vinyl ethyl sulfide.The effect of the reaction conditions (temperature, solvent, time, and ratio of reagents) on the yield of the products and the selectivity of the process was studied.
- Trofimov, B. A.,Amosova, S. V.,Nosyreva, V. V.,Voronkov, M. G.
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p. 2123 - 2127
(2007/10/02)
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- The Lithium Diisopropylamide-induced Fragmentation of 1,3-Dithiolane Derivatives of Several Ketones Having α-Hydrogen
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The reaction of 1,3-dithiolane derivatives of ketones having a-hydrogen with lithium diisopropylamide results in fragmentation to the corresponding thioketone followed by further conversion in a few steps to the other intermediate species which, on trapping with alkyl halide, leads to a vinylic sulfide and/or a sulfide bearing a secondary alkyl group.
- Ikehira, Hideyuki,Tanimoto, Shigeo,Oida, Tatsuo
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p. 2537 - 2538
(2007/10/02)
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- REACTION OF ETHYLTRITHIOCARBONATE AND TRITHIOCARBONATE IONS WITH ACETYLENES
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When heated with phenylacetylene in aqueous THF, potassium ethyltrithiocarbonate forms 1-phenyl-1-ethylthioethene in addition to cis-1-phenyl-2-ethylthioethene.The reaction takes place in DMSO, dioxane, benzene, and ethanol.It was established that cis-1-phenyl-2-ethylthioethene is formed exclusively in DMSO and 1-phenyl-1-ethylthioethene is formed in benzene.The reaction of potassium trithiocarbonate with ethylene in DMSO leads to divinyl sulfide.
- Ivanova, N. I.,Sigalov, M. V.,Amosova, S. V.,Trofimov, B. A.
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p. 451 - 454
(2007/10/02)
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- DIVINYL SULFIDE VIII. REACTIONS OF ACETYLENE WITH HYDROGEN SULFIDE IN ALKALI-DIMETHYL SULFOXIDE AND ALKALI-HEXAMETHYLPHOSPHOROTRIAMIDE SYSTEMS
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The reaction of acetylene with hydrogen sulfide in the alkali-metal hydroxide-dimethyl sulfoxide system, leading to divinyl sulfide, was realized.A preparative method was developed for the production of ethyl hydrosulfide from acetylene and hydrogen sulfide in the alkali-metal hydroxide-hexamethylphosphorotriamide system.
- Trofimov, B. A.,Amosova, S. V.,Kryuchkov, V. V.,Vasil'tsov, A. M.
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p. 1839 - 1841
(2007/10/02)
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