High-Temperature Synthesis of Thiophene from Bis(2-chloroethyl) Sulfide

Gas-phase reaction of bis(2-chloroethyl) sulfide (Yperite) with acetylene at 550–700°C leads to formation of thiophene in 45% yield, the conversion of the initial sulfide being complete. The yield of thiophene reaches 63–68% in the thermolysis of a mixture of acetylene, bis(2-chloroethyl) sulfide, and lower organic disulfides.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 6, 2005, pp. 910–912.Original Russian Text Copyright © 2005 by Voronkov, Levanova, Sukhomazova, Russavskaya, Deryagina, Korchevin.     

Synthesis of unsaturated organoselenium compounds via the reaction of organic diselenides with 2,3-dichloro-1-propene in the hydrazine hydrate-KOH system

Dimethyldiselenide reacts with 2,3-dichloro-1-propene at 20–25°C in the hydrazine hydrate-KOH medium to form 2-chloro-3-methylselanyl-1-propene with 90% yield. Diphenyldiselenide in the reaction with 2,3-dichloro-1-propene, depending on the conditions, can give quite selectively four products: 2-chloro-3-phenylselanyl-1-propene, phenylselanylpropadiene, 1-phenylselanyl-1-propyne, and Z-1,2-bis(phenylselanyl)-1-propene. The effect of the selenium atom on the reaction direction and the products structure is discussed.     

1,4-Dichalcogenins: Synthesis from Dichloroethenes and Elemental Chalcogens in a Hydrazine Hydrate–Potassium Hydroxide System

Russian Journal of General Chemistry - A possibility of the synthesis of 1,4-dichalcogenins by the reaction of vinylidene chloride or 1,2-dichloroethene with elemental chalcogenes in a hydrazine...     

Specific features of the reactions of 2,3-dichloro-1-propene with dibenzylchalcogenides in the system hydrazine hydrate-alkali

Dibenzyldisulfide and -diselenide react with 2,3-dichloro-1-propene in the system hydrazine hydrate-KOH by the domino mechanism: nucleophilic substitution of the allyl chlorine, dehydrochlorination with participation of the chlorine atom at the sp ²-carbon atom, allene-acetylene rearrangement, nucleophilic addition of the chalcogenide reagent to the triple bond. The effect of the nature of the chalcogen atom and the benzyl substituent on the studied domino reaction is discussed.     

Novel route to the synthesis of chalcogenolanes, chalcogenanes, and 1,2-dichalcogenaepanes*

The saturated heterocyclic compounds C₄H₈Y, C₅H₁₀Y, and C₅H₁₀Y₂ (Y = Se or Te) have been prepared by the reaction of 1,4-dibromobutane or 1,5-dibromopentane with potassium chalcogenides. The novelty of the route consists of the use of the hydrazine hydrate–KOH system for the reductive generation of potassium selenide, telluride, diselenide or ditelluride from elemental chalcogens.     

Stabilization of 1,2-ditellurolane by 2,3,5,6-tetramethylnitrosobenzene (Nitrosodurene)

1,2-Ditellurolane is an extremely unstable heterocyclic compound which can be maintained in solution in the presence of nitrosodurene for several days. It is proposed on the basis of UV spectroscopy and ¹H NMR spectroscopy that a complex is formed which determines the stability of 1,2-ditellurolane. It is shown that stabilized 1,2-ditellurolane can be used in organic synthesis. Presented to Academician of the Russian Academy of Sciences Boris Aleksandrovich Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, 1736–1738, November, 2008.     

Chalcogenation of 1,4-dichlorobut-2-yne with organic dichalcogenides in the system hydrazine hydrate–KOH

A reaction of organic dichalcogenides R₂Y₂ (R = Ph, Bn, Pr; Y = S, Se) with 1,4-dichlorobut-2-yne in the system hydrazine hydrate–KOH leads to four principal products: 1,4-bis(organylchalcogenyl)but-2-ynes, 1-organylchalcogenylbut-1-en-3-ynes, 4-organylchalcogenylbut-1-en-3-ynes, and 3(5)-methylpyrazole. The selectivity of the formation of individual products is determined by the ratio of the substrates used and the reaction temperature. A plausible mechanism of chalcogenation considered in the work agrees with the effect of the nature of chalcogene atoms and organic substituents R on stability of intermediates and products. The stabilization of carbanions by α chalcogene-containing groups corresponds to the following order: PhS > PhSe > BnS > BnSe > PrS.     

Reactions of 2,3-dichloro-1-propene with sulfur and tellurium in the system hydrazine hydrate-KOH

2,3-Dichloro-1-propene reacts with sulfur dissolved in the system hydrazine hydrate-KOH (with formation of K₂S₂ or K₂S) to afford bis(2-chloro-1-propene-3-yl)sulfide as the main product in both cases. Under similar conditions tellurium induces β-elimination of both chlorine atoms resulting in the formation of allene and complete regeneration of tellurium metal.     

Synthesis and oxidative cleavage of poly(trimethylene diselenides)

1-Bromo-3-chloropropane and elemental selenium react in hydrazine hydrate-alkali and hydrazine hydrate-amine systems to form poly(trimethylene diselenides). The reductive cleavage of the resulting selenokols yielded 1,3-propanediselenol, 1,2-diselenolane, and bis(alkylseleno)propanes. These compounds are important reagents for organic synthesis and ligands for complex formation. The products obtained were studided by GC-MS.