System Hydrazine Hydrate-alkali Research Articles

Reactions of 1,1-Dichloroethene with elemental chalcogens in the system hydrazine hydrate–alkali

Reactions of 1,1-Dichloroethene with elemental chalcogens in the system hydrazine hydrate–alkali

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 sp2-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.

Reaction of tellurium with dichloromethane in the system hydrazine hydrate-alkali

Tellurium reacts with dichloromethane in the system hydrazine hydrate-alkali substituting one chlorine atom by tellurium whereas the second chlorine atom undergoes reductive substitution by hydrogen leading to the formation of methyltellanyl derivatives. Tentative mechanism of reduction is discussed. The discovered reaction allows the preparation of organotellurium compounds containing the MeTe group, including those involving other chalcogens.

Reaction of tellurium with 2,3-dichloro-1-propene in the system hydrazine hydrate-alkali. A novel approach to synthesis of allene

Reaction of tellurium with 2,3-dichloro-1-propene in the system hydrazine hydrate-alkali. A novel approach to synthesis of allene

Reactions of dichloromethane with chalcogens and dimethyl chalcogenides in the hydrazine hydrate-alkali system

Methods of synthesis of compounds MeY(CH2Y) n Me (Y=S, Se, Te; n = 1–3) containing several identical or different chalcogen atoms are suggested. The methods are based on the reactions of dichloromethane with elemental chalcogens (Y2−) and dimethyl dichalcogenides (MeY−) activated in the system hydrazine hydrate-alkali. The effect of the chalcogen on the reactivity toward dichloromethane is qualitatively assessed. With elemental tellurium in the system hydrazine hydrate-alkali, reduction of one chlorine atom in dichloromethane and formation of methyltellanyl derivatives are observed.

Synthesis of 1,3-bis(organylchalcogeno)propanes and 1,2-dichalcogenolanes having different chalcogen atoms in the molecule

Oligomeric trimethylene dichalcogenides and the corresponding 1,2-dichalcogenolanes having both similar and different chalcogen atoms in the molecule were synthesized by reactions of 1-bromo-3-chloropropanes with two elemental chalcogens (S, Se; S, Te; Se, Te) activated by the system hydrazine hydrate-alkali. Reductive cleavage of the oligomeric products in the system hydrazine hydrate-alkali, followed by alkylation with methyl iodide or ethyl bromide gave 1,3-bis(alkylchalcogeno)propanes. The latter were also obtained from the corresponding dialkyl dichalcogenides and 1-bromo-3-chloropropane in the alkaline reducing system.

Formation of telluretane and 1,5-ditelluracyclooctane in the reaction of tellurium with 1-bromo-3-chloropropane in the system hydrazine hydrate-alkali

Formation of telluretane and 1,5-ditelluracyclooctane in the reaction of tellurium with 1-bromo-3-chloropropane in the system hydrazine hydrate-alkali

Reaction of Diethyl Diselenide with Dihaloalkanes in an Alkaline Reductive Medium

Bis(ethylseleno)alkanes were obtained by reductive cleavage of the Se-Se bond in diethyl diselenide with the system hydrazine hydrate-alkali, followed by alkylation with dihaloalkanes. A general preparative method of synthesis of bis(alkylseleno)alkanes of various structure was proposed.

Reaction of Aldehydes with Hydrazine in the System Sulfur—Alkali.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Reactions of Bielectrophiles (ClCH2CH2)2Y with Sulfur in Basic Reducing Systems

A simple procedure was developed for preparing bis(β-mercaptoethyl) ether and bis(β-ecraptoethyl) sulfide from commercially available chemicals: elemental sulfur, alkali, and bis(β-chloroethyl) ether or sulfide, based on thiylation with elemental sulfur of these substrates in the aqueous system hydrazine hydratealkali, with initial formation of the corresponding polysulfide polymers (thiokols). Their reduction with the system hydrazine hydrate-alkali, followed by acidification of dithiolate anions, yields the corresponding dithiols. Thiokols based on bis(β-chloroethyl) ether are soluble in organic solvents; they were studied by 1H NMR.

Reaction of Aldehydes with Hydrazine in the System Sulfur-Alkali

Dissolution of sulfur in the system hydrazine hydrate-alkali leads to strong activation of hydrazine, so that the latter readily reacts at room temperature with aldehydes of the aromatic and thiophene series to give the corresponding aldehyde azines in high yield. The mechanism of activating effect of sulfur is discussed.

Reactions of Diorganyl Disulfides with Dihaloalkanes in Basic Reductive Media. Synthesis of Bis(organylthio)alkanes

A convenient preparative synthesis of bis(organylthio)alkanes was developed. It is based on alkylation with dihaloalkanes of solutions of diorganyl disulfides in the basic reductive system hydrazine hydrate-alkali. The generation of organylthiolate anions from disulfides and the subsequent reaction of the anions with dihaloalkanes are performed in one reaction vessel without isolation of intermediate alkali metal thiolates. At the same time, the reactions of diphenyl or dithienyl disulfides with dihaloalkanes result in substitution with the thiolate anions of only one halogen atom to give the corresponding unsymmetrical sulfides. In certain cases in the presence of excess alkali the latter sulfides are dehalogenated to form alkyl vinyl sulfides.