Synthesis of 5-mercapto-1,2-dithiole-3-thiones and their transformation into 5-chloro-1,2-dithiol-3-ones

A number of 4-dialkylamino-5-mercapto-1,2-dithiole-3-thiones were synthesized by reactions of alkyl(diisopropyl)amines with S₂Cl₂. Their reactions with S₂Cl₂—DABCO unexpectedly gave 5-chloro-4-dialkylamino-1,2-dithiol-3-ones. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 143–147, January, 2006.     

Synthesis and Crystal Structure of (Z)-Ethyl 5-(phenylamino)-3-(phenylimino)-3H-1,2-dithiole-4-carboxylate

The compound (Z)-ethyl 5-(phenylamino)-3-(phenylimino)-3H-1,2-dithiole-4-carboxylate 3 has been synthesized by the reaction of ethylacetoacetate 1 and phenylisothiocyanate 2. Its structure has been established by ¹H NMR, ¹³C NMR, infrared, mass spectra, and x-ray crystallography.      

New Cycloadditon Reaction of 2-Chloroprop-2-enethioamides with Dialkyl Acetylenedicarboxylates: Synthesis of Dialkyl 2-[4,5-bis(alkoxycarbonyl)-2-(aryl{alkyl}imino)-3(2H)-thienylidene]-1,3-dithiole-4,5-dicarboxylates

The 1,3-dipolar cycloaddition of 1,2-dithiole-3-thiones with alkynes to form 1,3-dithioles is one of the most studied reactions in this class of polysulfur-containing heterocycles. Nucleophilic substitution of chlorine atoms in dimethyl 2-(1,2-dichloro-2-thioxoethylidene)-1,3-dithiole-4,5-dicarboxylate, which was obtained by addition one molecules of DMAD to 4,5-dichloro-3H-1,2-dithiole-3-thione, led to a series of 2-chloro-2-(1,3-dithiol-2-ylidene)ethanethioamides. Cycloaddition reaction of 2-chloro-2-(1,3-dithiol-2-ylidene)ethanethioamides with activated alkynes led to the unexpected formation of 2-(thiophen-3(2H)-ylidene)-1,3-dithioles via new intermediate, 1-(1,3-dithiol-2-ylidene)-N-phenylethan-1-yliumimidothioate. Structure of dimethyl 2-(4,5-bis(methoxycarbonyl)-2-(phenylimino)thiophen-3(2H)-ylidene)-1,3-dithiole-4,5-dicarboxylate was finally proven by single crystal X-ray diffraction study. Optimized reaction conditions and a mechanistic rationale for the 1,3-dipolar cycloaddition of novel intermediate are presented.     

Addition compounds of nucleophiles and 3-ethylthio-6-oxo-6H-1,2-dithiolo[4,3-c]1,2-dithiolium tetrafluoroborate. Synthesis of 3H,6H-1,2-dithiolo[4,3-c]1,2-dithiole-3-one-6-thione

Summary A smooth method of synthesizing 3H, 6H-1,2-dithiolo[4,3-c]1,2-dithiole-3,6-dithione (3), and also its partial desulfuration to yield 3H, 6H-1,2-dithiolo[4,3-c]1,2-dithiole-3-one-6-thione (4) is presented. The ethylation product5 of the monothione4 reacts with various nucleophilic reagents to form remarkably stable adducts. The adducts of5 with methanol,tert-butyl mercaptan, and with aniline could be isolated and characterized by their¹H-NMR spectra.

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Anlagerungsverbindungen von Nukleophilen an 3-Ethylthio-6-oxo-6H-1,2-dithiolo[4,3-c]1,2-dithioliumtetrafluoroborat. Synthese von 3H,6H-1,2-Dithiolo[4,3-c]1,2-dithiol-3-on-6-thion

Zusammenfassung Eine glatte Synthese für 3H,6H-1,2-Dithiolo[4,3-c]1,2-dithiol-3,6-dithion (3) und für dessen partielle Entschwefelung zu 3H,6H-1,2-Dithiolo[4,3-c]1,2-dithiol-3-on-6-thion (4) wird angegeben. Das Ethylierungsprodukt5 des Monothions4 reagiert mit unterschiedlichen Nukleophilen zu bemerkenswert stabilen Addukten. Die Addukte mit Methanol,tert.-Butylmercaptan und mit Anilin wurden isoliert und durch ihr¹H-NMR-Spektrum charakterisiert.

     

Selective synthesis of bis[1,2]dithiolo[1,4]thiazines from 4-isopropylamino-5-chloro-1,2-dithiole-3-ones

Reaction of 4-isopropylamino-5-chloro-1,2-dithiole-3-ones 3 and S₂Cl₂ in acetonitrile gave selectively 3-oxo-bis[1,2]dithiolo[1,4]thiazine-5-thiones 1 by the addition of triethylamine and bis[1,2]dithiolo[1,4]thiazine-3,5-diones 5 under the action of formic acid. 3,5-Diones 5 were also obtained by intramolecular cyclization of N,N-bis(5-chloro-3-oxo[1,2]dithiol-4-yl)amines 6 with S₂Cl₂ in the presence of Et₃N.     

Convenient method for the synthesis of 5-(4-methoxyphenyl)-3H-1,2-dithiole-3-thione (ADT-OMe) and 5-(4-hydroxyphenyl)-3H-1,2-dithiol-3-thione (ADT-OH) using microwave irradiation

A convenient method is described for the rapid synthesis of 5-(4-methoxyphenyl)-3H-1,2-dithiole-3-thione (ADT-OMe) from anethole and elemental sulfur using microwave irradiation. Various reaction conditions were applied to reduce the reaction time from several hours to 10 min, resulting in an improvement in yield and overcoming the undesired by-product formation associated with conventional methods. 5-(4-Hydroxyphenyl)-3H-1,2-dithiol-3-thione (ADT-OH) was obtained by the deprotection of ADT-OMe using pyridine hydrochloride under microwave irradiation.     

Photooxidation of Transition Metal Complexes of 1,3-Dithiole-2-thione-4,5-dithiolate (dmit) and 1,2-Dithiole-3-thione-4,5-dithiolate (dmt)

Metall(II) bis-chelates of 1,3-dithiole-2-thione-4,5-dithiolate (dmit) and 1,2-dithiole-3-thione-4,5-dithiolate (dmt) undergo in CHCl₃/CH₃CN (ratio 1:24) photooxidation to the metal(III) bis-chelates when irradiated at 313 nm. No side reactions were observed. There is no correlation between the quantum yields of photooxidation and the electrochemical halve-wave potentials. This holds also in comparison to maleonitriledithiolato chelates.     

A convenient route to 4-mercapto-1,2-dithiole-3-thiones from terminal alkynes

4-Mercapto-1,2-dithiole-3-thiones are easily prepared by deprotonation of terminal alkynes followed by sequential treatment with carbon disulfide, sulfur and acid; addition of alkylating agents at the last stage gives 4-alkylthio-1,2-dithiole-3-thiones instead.     

Synthesis and Anticancer Activity of 5-(1,2-Diselenolan-3-Yl)pentanoic Acid and its Derivatives

Abstract

A green and high-yielding synthetic route for the preparation of 5-(1,2-diselenolan-3-yl)pentanoic acid (SeA) was reported. Some SeA derivatives, N′-substituted benzylidene-5-(1,2-diselenolan-3-yl)pentanehydrazide, were prepared, and they were screened for their anticancer activity against human breast MCF-7, leukemia HL-60, cervixuterus Hela, and placental villus Bewo cancer cell lines. The minimum inhibitory concentrations (MICs) of the synthetic compounds showed moderate anticancer activity at low concentrations (0.5–5 μg/mL).     

Convenient one-pot syntheses of 1,2-dithiole-3-thiones and 3-imino-1,2-dithioles from terminal alkynes

The reaction of acetylide anions with carbon disulfide or phenyl isothiocyanate followed by addition of sulfur in the presence of a protonating agent such as a primary amine or alcohol affords 1,2-dithiole-3-thiones or 3-imino-1,2-dithioles in good to excellent yields.     

新型二硫杂环戊烯硫酮化合物的合成及其对谷氨酸诱导损伤HT22细胞的保护作用

在保留ADT-OH的3H-1,2-二硫杂环戊烯-3-硫酮结构的基础上,用芳乙烯基替换4-羟基苯环,设计并合成了6个二硫杂环戊烯硫酮化合物（L₁~L₆,其中L₂, L₃, L₅和L₆为新化合物）,其结构经¹H NMR, ¹³C NMR和HR-MS(ESI)表征。采用MTT法研究了L₁~L₆对谷氨酸诱导损伤的海马神经元HT22细胞的影响。药理初筛结果表明:给药浓度为10~100 μmol·L^-1时,L₁, L₂, L₄和L₆均能提高受损HT22细胞的存活率(P<0.01);给药浓度为1 μmol·L^-1时,L₃和L₅均可提高损伤HT22细胞的存活率(P<0.01)。     

Reduction of 4-fluoro-5-(1,1,2,2-tetrafluoroethyl)-3H-1,2-dithiole-3-thione with sodium sulfide: Synthesis of fluoro-containing sulfur-rich heterocycles

Treatment of 4-fluoro-5-(1,1,2,2-tetrafluoroethyl)-3H-1,2-dithiole-3-thione with 2 equivalents of sodium sulfide gives after acidification 3,4-difluoro-2-mercapto-1,6,6aλ⁴-trithiapentalene, which can be further reduced by sodium sulfide to 3,5-difluoro-4-mercapto-thiopyran-2-thione.     

Bifunctionalized allenes. Part XXI. Electrophilic cyclization and addition reactions of 3-(α- or β-hydroxyalkyl)-allenylphosphonates and allenyl phosphine oxides

Abstract

The present paper discusses the electrophilic cyclization and addition reactions of 3-(α- or β-hydroxyalkyl)-allenylphosphonates and phosphine oxides. Treatment of 3-(α- or β-hydroxy-alkyl)-allenylphosphonates with electrophiles takes place with 5-endo-trig cyclization and gives 2-methoxy-2,5-dihydro-1,2-oxaphosphole 2-oxides as a result of the neighboring phosphonate group participation in the electrophilic cyclization. On the other hand, 3-(α- or β-hydroxyalkyl)-alk-(1E)-en-1-yl phosphine oxides were prepared by chemo-, regio-, and stereoselective electrophilic addition to the C²-C³-double bond in the 3-(α- or β-hydroxyalkyl)-alka-1,2-dienyl phosphine oxides and subsequent attack of the external nucleophile (halide anion). The paper proposes a possible mechanism that involves electrophilic cyclization and addition reactions of the phosphorylated (α- or β-hydroxyalkyl)allenes.     

Reaction of 1,2-diarylhydrazines with acetic anhydride catalyzed by 4-(dimethylamino)pyridine

Summary A new method for the synthesis of 1,2-diaryl-1,2-dihydro-5-methyl-3H-pyrazol-3-ones3 and 4-acetyl-1,2-diaryl-1,2-dihydro-5-methyl-3H-pyrazol-3-ones5 is presented. The reaction of 4,4-disubstituted 1,2-diarylhydrazines1 with acetic anhydride in the presence of an equimolar amount of 4-(dimethylamino)pyridine leads to mixtures of the corresponding acetyl derivatives2 and3. Under the same conditions, 2,2-disubstituted 1,2-diarylhydrazines yield mixtures of3 and5.

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4-(Dimethylamino)pyridin-katalysierte Reaktion von 1,2-Diarylhydrazinen mit Essigsäureanhydrid

Zusammenfassung Eine neue Methode zur Synthese von 1,2-Diaryl-1,2-dihydro-5-methyl-3H-pyrazol-3-onen3 und 4-Acetyl-1,2-diaryl-1,2-dihydro-5-methyl-3H-pyrazol-3-onen5 wird beschrieben. Die Reaktion von 4,4-disubstituierten 1,2-Diaryl-hydrazinen1 mit Essigsäureanhydrid führt in Gegenwart eines Äquivalentes 4-(Dimethylamino)pyridin zu Gemischen der entsprechenden Acetylderivate2 und3. Unter den gleichen Bedingungen werden aus 2,2-disubstituierten 1,2-Diarylhydrazinen Gemische aus3 und5 erhalten.

     

Photochromic dihetarylethenes

The structures of two hetarylethene photochromes,viz., 1,2-bis(2-ethyl-5-ethylsulfonylthien-3-yl)perfluorocyclopentene and 1,2-bis[5-(benzoxazol-2-yl)-2-methylthien-3-yl]perfluorocyclopentene, were established by X-ray diffraction analysis. The conformational parameters of the title compounds are considered. The cyclopentene ring in the former compound is planar and this ring in the latter compound adopts an envelope conformation. There are no overall conjugated systems in the molecules under study. In both structures, the dihetaryl fragments are rotated with respect to the perfluorocyclopentene fragments by ∼55°. The thiophene and benzoxazole rings in 1,2-bis[5-(benzoxazol-2-yl)-2-methylthien-3-yl]perfluorocyclopentene are coplanar. For Part 3, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 74–77, January, 2000.     

Photochromic dihetarylethenes

The structures of two hetarylethene photochromes,viz., 1,2-bis(2-ethyl-5-ethylsulfonylthien-3-yl)perfluorocyclopentene and 1,2-bis[5-(benzoxazol-2-yl)-2-methylthien-3-yl]perfluorocyclopentene, were established by X-ray diffraction analysis. The conformational parameters of the title compounds are considered. The cyclopentene ring in the former compound is planar and this ring in the latter compound adopts an envelope conformation. There are no overall conjugated systems in the molecules under study. In both structures, the dihetaryl fragments are rotated with respect to the perfluorocyclopentene fragments by ∼55°. The thiophene and benzoxazole rings in 1,2-bis[5-(benzoxazol-2-yl)-2-methylthien-3-yl]perfluorocyclopentene are coplanar. For Part 3, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 74–77, January, 2000.     

New approach to the synthesis of 4-amino-2-pyridone and 1-phenyl-1,6-naphthyridinone derivatives based on substituted 3-and 5-formyl-2-pyridones

The reactions of 3-cyano-3(5)-formyl-2-oxo-4-(phenylamino)-1,2-dihydropyridines with CH acids were studied. The previously unknown fused 2-pyridone derivatives containing the 4-aminopyridine fragment were synthesized by the Knoevenagel reaction. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1416-1420, August, 2006.     

Convenient synthesis of 4H-chromenyl-tetrahydro-2H-pyrancarboxylates and cleavage of chromone and pyran rings leading to 5-(2-hydroxybenzoyl)-2-(trifluoromethyl)-1,2-dihydropyridine-3-carboxylates

4H-Chromenyl-tetrahydro-2H-pyrancarboxylates 3a–k have been conveniently prepared by the reaction of 3-formylchromones 1a–k and ethyl 4,4,4-trifluoro-3-oxobutanoate 2a with good yields. Thus obtained 4H-chromenyl-tetrahydro-2H-pyrancarboxylates 3a–k were reacted with amines 4a–e to provide series of 5-(2-hydroxybenzoyl)-2-(trifluoromethyl)-1,2-dihydropyridine-3-carboxylates 5a–o. The reaction proceeded via Michael addition (C-N bond formation) and followed by cleavage of chromone and pyran rings (C-O bond cleavage) in one pot.