- Reduction of thiophenes in the presence of sulfuric acid and zinc
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Alkyl-substituted thiophenes are hydrogenated by the Zn-H 2SO4 system to the corresponding 2,5-di- hydrothiophenes and thiophanes. In the case of 2-formyl- and 2-acetylthiophene it was established that in substituted thiophenes simul
- Latypova,Parfenova,Lyapina
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- Organosulfur Chemistry. II. Use of Dimethyl Sulfoxide; a Facile Synthesis of Cyclic Sulfides
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A versatile and short-reaction-time synthesis of twelve four-, five- and six-membered thiacycloalkanes (IIa-l)from the appropriate α,ω-dibromoalkanes (Ia-l)has been developed.Technical-grade dimethyl sulfoxide was proved to be by far the best for this cyclization.The pronounced effect for ring formation was recognized to be in order of five-membered ring (thiolanes) > six-membered ring (thianes) > four-membered ring (thietanes).Startling were 2-methylthiolane (IIf) and 2,5-dimethylthiolane (IIg; cis/trans mixture), both obtained in high yields although α-methyl - and α,α'-dimethyl substitution in general showing a remarkable retardation for cyclization.On the other hand, in both 3,3-dimethylthietane (IId) and 4,4-dimethylthiane (IIl) cyclization was much more efficient than other counterparts in each series, which is referred to as the gem-dimethyl effect.Keywords: thiacycloalkane; thietane; thiolane; thiane; dimethyl sulfoxide; cyclization: α,ω-dibromoalkane; sodium sulfide nonahydrate; refractive index
- Nagasawa, Kazuo,Yoneta, Akemi
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p. 5048 - 5052
(2007/10/02)
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- FORMATION OF SULPHUR COMPOUNDS IN THE HYDRODENITROGENATION OF 2-METHYLQUINOLINE, 2-METHYLPIPERIDINE, INDOLE, AND ISOQUINOLINE ON A NICKEL-TUNGSTEN CATALYST IN THE PRESENCE OF HYDROGEN SULPHIDE
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2-Methylquinoline, 2-methylpiperidine, indole, and isoquinoline were subjected to hydrodenitrogenation (HDN) on a sulphidized nickel-tungsten catalyst in an autoclave at 300 and 350 deg C using pure hydrogen or a hydrogen-hydrogen sulphide mixture.The neutral fraction from the HDN of 2-methylquinoline and 2-methylpiperidine contained 40 and 90percent sulphur compounds, respectively.The presence of hydrogen sulphide in the HDN of isoquinoline resulted in an enhanced fraction of the neutral moiety.A reaction mechanism is suggested for the HDN of 2-methylquinoline and 2-methylpiperidine in the presence of hydrogen sulphide, in which the latter contributes to the higher degree of conversion due to the formation of corresponding sulphur compounds.
- Cerny, Mirko,Trka, Antonin
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p. 3413 - 3420
(2007/10/02)
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- REACTION OF SULFUR HALIDES WITH UNSATURATED COMPOUNDS XV. 2,2'-DICHLORO SULFIDES IN REACTION WITH ORGANOALUMINUM COMPOUNDS
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The reaction of 2,2'-dichloro sulfides with organoaluminum compounds was investigated.The reaction leads to dechlorination or alkylation products, depending on the structure of the organoaluminum compounds.It was established that nickel, titanium, and zirconium compounds have catalytic activity and enabled the reactions to occur under milder conditions.The addition of sulfur dichloride to 1-methyl- and 1,5-dimethyl-1,5-cyclooctadienes was investigated, and the rearrangement was followed in the series of 9-thiabicyclononane derivatives.
- Tolstikov, G. A.,Kantyukova, R. G.,Spirikhin, L. V.
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p. 1210 - 1218
(2007/10/02)
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