Regioselective Synthesis of 3-[2-(Alkylsulfanyl)ethyl]pyrazoles by Reaction of Alkanethiols with 3-Alkenylpyrazoles

3-Alkenyl-5-chloropyrazoles reacted with alkanethiols on heating to 60°C to afford in good yields 3-[2-(alkylsulfanyl)ethyl]-5-chloropyrazoles as a result of anti-Markovnikov addition to the alkenyl group.     

Synthesis of new 2-(alkenylsulfanyl)pyrimidine derivatives

Isothiuronium salts prepared by treatment of allyl bromide, 2,3- and 1,3-dichloropropenes, and 1,3-dichlorobut-2-ene with thiourea reacted with pentane-2,4-dione and 4,4,4-trifluoro-1-(thiophen-2-yl)-butane-1,3-dione to afford new pyrimidine derivatives, 2-(alkenylsulfanyl)-4,6-dimethyl- and 2-(alkenylsulfanyl)-4-(thiophen-2-yl)-6-(trifluoromethyl)pyrimidines.     

Reactions of <Emphasis Type="Italic">N</Emphasis>-(2,2,2-trichloroethylidene)- and <Emphasis Type="Italic">N</Emphasis>-(2,2-dichloro-2-phenylethylidene)arenesulfonamides with biuret

N-(2,2,2-Trichloroethylidene)- and N-(2,2-dichloro-2-phenylethylidene)arenesulfonamides react with an equimolar amount of biuret to give 1-(1-arylsulfonylamino-2,2,2-trichloroethyl)- or 1-(1-arylsulfonylamino-2,2-dichloro-2-phenylethyl)biurets. The reactions with 2 equiv of N-(polychloroethylidene)arenesulfonamides involve both amino groups in the biuret molecule, yielding the corresponding 1,5-bis(1-arylsulfonylamino-2,2,2-trichloroethyl)- and 1,5-bis(1-arylsulfonylamino-2,2-dichloro-2-phenylethyl)biurets.     

Reaction of 1,3- and 2,3-dichloroprop-1-enes with dipotassium propane-1,3-ditellurolate in the system hydrazine hydrate-KOH

Russian Journal of Organic Chemistry -     

3-Alkenyl-5-chloropyrazoles: expedient synthesis via heterocyclization of 1,1-dichloro-4-halo-1-alken-3-ones with hydrazines

Synthesis of hard-to-reach 5-chloro-3-alkenylpyrazoles was developed via heterocyclization of alkyl-, benzyl- or dialkylhydrazines with 1,1-dichloro-4-halo-1-alken-3-ones obtained from haloacyl chlorides and vinylidene chloride. The reaction process includes the formation of intermediate 5-chloro-3-(1-haloalkyl)pyrazoles followed by dehydrohalogenation.     

Reduction of <Emphasis Type="Italic">N</Emphasis>-(polychloroethylidene)- and <Emphasis Type="Italic">N</Emphasis>-(1-hydroxypolychloroethyl) arenesulfonamides with adamantane in the presence of superacids

N-(2,2,2-Trichloroethylidene)-, N-(2,2-dichloro-2-phenylethylidene)-, and N-(1-hydroxy-2-polychloroethyl) arenesulfonamides reacted with adamantane in carbon tetrachloride in the presence of oleum or concd. H₂SO₄-P₄O₁₀ mixture to give the corresponding N-(2-polychloroethyl)arenesulfonamides as a result of reduc-tion of the azomethine and OH group, respectively.     

Functionalization of highly electrophilic <Emphasis Type="Italic">N</Emphasis>-(2,2,2-trichloroethylidene)- and <Emphasis Type="Italic">N</Emphasis>-(2,2-dichloro-2-phenylethylidene) arenesulfonamides with dithiooxamide

Depending on the reactant ratio, dithiooxamide (ethanedithioamide) reacted as N-nucleophile or N,N′-binucleophile with highly electrophilic aldimines, N-(2,2,2-trichloroethylidene)- and N-(2,2-dichloro-2-phenylethylidene)arenesulfonamides, to give the corresponding mono- or bis-adducts, N-[2-polychloro-1-(arylsulfonylamino) ethyl]ethanedithioamides or N,N′-bis[2-polychloro-1-(arylsulfonylamino)ethyl]ethanedithioamides, in good yield.     

α-Functionally Substituted α,β-Unsaturated Aldehydes as Fine Chemicals Reagents: Synthesis and Application

α-Functionalized α,β-unsaturated aldehydes is an important class of compounds, which are widely used in fine organic synthesis, biology, medicine and pharmacology, chemical industry, and agriculture. Some of the 2-substituted 2-alkenals are found to be the key metabolites in plant and animal cells. Therefore, the development of efficient methods for their synthesis attracts the attention of organic chemists. This review focusses on the recent advances in the synthesis of 2-functionally substituted 2-alkenals. The approaches to the preparation of α-alkyl α,β-unsaturated aldehydes are not included in this review.     

A novel regiospecific cascade synthesis of sulfonamide derivatives from <Emphasis Type="Italic">N</Emphasis>-(2-polychloroethyl)sulfonamides via chloroaziridine intermediates in the presence of mercaptoethanol

N-(1-Aryl-2-polychloroethyl)arenesulfonamides obtained on the basis of N,N-dichlorosulfoamides and polychloroethenes or phenylacetylene undergo a reaction cascade in the presence of mercaptoethanol. The reaction cascade opens a new route to the series of cyclic or open-chain sulfonamide derivatives. The process includes cyclization to aziridine intermediates, their further recyclization, and isomerization to imidoylchlorides or chloroimines, followed by substitution or reduction under the action of mercaptoethanol or hydrolysis. The final sulfonamide structures depend on the starting N-(polychloroethyl)sulfonamides. N-(2,2-Dichloroethyl)sulfonamides were transformed into sulfonamide-containing 1,4-oxathians while N-(2,2,2-trichloroethyl)sulfonamides were converted to N-(2-arylacetyl)arenesulfonamides. N-(2-Phenyl-2,2-dichloroethyl)sulfonamides form enamide derivatives that were transformed into aromatic ketones.