A one-pot, three-component synthesis of thiazolidine-2-thiones

An efficient method for the synthesis of thiazolidine-2-thiones is described via regiospecific iodocyclization of an allyl amine, carbon disulfide, and iodine. Dehydrohalogenation of the iodo-derivatives gives thiazole-2(3H)-thiones. In addition, nucleophilic substitution of the iodine in the products is accomplished using NaN₃, thiophenol, or dithiocarbamate.     

Convenient approach to chiral 4-monosubstituted 1,3-oxazolidine-2-thiones

Chiral 4-monosubstituted 1,3-oxazolidine-2-thiones are regarded as one of the modified version of Evans auxiliaries in asymmetric aldol condensation, which can generate two adjacent chiral carbon centers in one time They have advantages over Evans auxiliaries in some aspects, however, their application is highly limited by their preparation approaches as toxic or flammable chemicals are involved. Here, a mild and applicable procedure for preparing the chiral oxazolidine-2-thione auxiliaries has been developed in this article. Potassium ethylxanthate and the corresponding chiral amino alcohols as the starting material in absolute ethanol are mixed and the mixture are heated under reflux for 1?h in open air to provide 1,3-oxazolidine-2-thiones chiral auxiliaries in moderate to excellent yields.     

The Action of Carbon Disulfide and Sulfur on Enamines,Ketimines, and CH Acids

The reaction of sulfur, carbon disulfide, and enamines at room temperature leads mainly or exclusively to 3H-1,2-dithiole-3-thiones; these are occasionally accompanied by 2H-1,3-dithiole-2-thiones, which can also be prepared by a modified procedure. Many enamines react with sulfur at room temperature to form thioamides. At about 50°C, enamines of acetophenone give 2-benzylidene-4-phenyl-2H-1,3-dithiol. The action of isothiocyanates and sulfur on enamines leads to the formation of thiazolidine-2-thiones. 2H-Thiopyran-2-thiones can be prepaAred from enamines or dienamines with carbon disulfide at room temperature. The reaction of ketimines (Schiff bases) with carbon disulfide and sulfur yields 3H-1,2-dithiole-3-thiones or isothiazoline-5-thiones. The reaction of alkynes with sulfur and carbon disulfide leads to 2H-1,3-dithiole-2-thiones. Nitriles containing active methylene groups react with carbon disulfide and sulfur to form 5-amino-3H-1,2-dithiole-3-thiones. When isothiocyanates are used instead of CS₂, the reaction leads to δ⁴-4-amino-thiazoline-2-thiones.     

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.     

A facile access to chiral 4-isopropyl-, 4-benzyl-, and 4-phenyloxazolidine-2-thione

A highly practical procedure for preparing the chiral oxazolidine-2-thione auxiliaries using carbon disulfide and the corresponding chiral amino alcohols as the starting materials in the presence of potassium carbonate and hydrogen peroxide is presented.     

N-2-多氟烷基乙基取代1,3,4-噁二唑-2-硫酮及1,2,4-三唑-5-硫酮类化合物的合成和密度泛函理论研究

为改善二唑及三唑类化合物的生物活性, 设计合成了一系列多氟烷基乙基取代的1,3,4-噁二唑-2-硫酮6a～6l及1,2,4-三唑-5-硫酮类化合物9a～9l. ¹H NMR, ¹⁹F NMR, IR和MS谱以及元素分析表征了它们的结构; 实验结果与Materials Studio 3.0中的Dmol3计算模块理论计算表明了唑环上的NH较之CONH中的NH更易进行烷基化反应.     

Absence of the Thorpe-Ingold Effect by gem-Diphenyl Groups in Ring-Closing Enyne Metathesis

In tandem ring-closing metathesis of alkynyl silaketals containing two different tethered olefins, the gem-dimethyl group showed the expected Thorpe-Ingold effect, thereby giving good level of group selectivity. Unexpectedly, however, the corresponding gem-diphenyl group did not show any Thorpe-Ingold effect for the ring-closure reaction.     

Synthesis of corrosion preventive long-chain N -alkyl-2-(phenylthio)-acetohydrazides and 2-oxo-2-phenylethyl-2-alkanoylhydrazinecarbodithioates

Long-chain N-alkyl-2-(phenylthio)acetohydrazides were synthesized via the reactions of 2-(phenylthio)acetohydrazide with long-straight-chain aldehydes and then reduction with sodium borohydride. The reactions of long-straight-chain hydrazides with carbon disulfide in alkaline media give the corresponding carbodithioate salts. Heating of potassium 2-alkanoylhydrazinecarbodithioates with phenacyl bromide do not yield cyclization and failed to give the corresponding long-chain thiazolidine-2-thiones, but gave the corresponding 2-oxo-2-phenylethyl-2-alkanoylhydrazinecarbodithioates via nucleophilic substitution reaction. In addition, the synthesized compounds were tested for their corrosion prevention capabilities in acidic or in mineral oil media.     

1,4-Dithiafulvene aus der Umsetzung von 4,4-disubstituierten 1,3-Thiazol-5(4H)-thionen mit Acetylenderivaten

1,4-Dithiafulvenes, Products of the Reaction of 4,4-Disubstituted 1,3-Thiazol-5(4H)-thiones and Acetylenic Compounds On heating in toluene, 4,4-disubstituted 1,3-thiazol-5(4H)-thiones 1 and acetylenecarboxylates or acetylenecarbonitriles 2 undergo a cyclosubstitution reaction to yield 2-methylidene-1,3-dithiol derivatives 3 (1,4-dithiafulvenes) and a nitrile. Further heating of 3a and 3b in the presence of excess 2a leads to the isomeric 2,3-dihydrothiophene-2-thiones 4a and 4b , respectively. The benzodithiafulvene 14 has been formed in a similar reaction from 1a and in situ generate benzyne.     

A novel multicomponent approach to the synthesis of 1,3-thiazolidine-2-thiones

An easy, efficient, and simple one-pot approach for the synthesis of 1,3-thiazolidine-2-thiones via multicomponent reaction is reported. The reaction of a primary amine with carbon disulfide in the presence of dibenzoylacetylene or bis(4-methyl-1-benzoyl)acetylene in a mixture of CH₂Cl₂ and H₂O after 5 h, afforded the title compound as alkene diastereomers.     

A Convenient Synthesis of Thiazolidin-2-ones from Thiazolidine-2-thiones: Antibiotic Activity and Revisiting the Mechanism

Abstract

Various substituted thiazolidin-2-ones were synthesized from the corresponding thiazolidine-2-thiones with bromoethanol in ethanol with sodium ethoxide as a base. The optimal reaction conditions and mechanism were reinvestigated in detail. The bioassay indicated that (S)-4-isobutyl and (S)-4-benzylthiazolidin-2-ones show certain inhibitive activities against Candida albicans and Escherichia coli.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

GRAPHICAL ABSTRACT     

Synthesis of corrosion preventive long-chain <Emphasis Type="Italic">N</Emphasis>-alkyl-2-(phenylthio)-acetohydrazides and 2-oxo-2-phenylethyl-2-alkanoylhydrazinecarbodithioates

Long-chain N-alkyl-2-(phenylthio)acetohydrazides were synthesized via the reactions of 2-(phenylthio)acetohydrazide with long-straight-chain aldehydes and then reduction with sodium borohydride. The reactions of long-straight-chain hydrazides with carbon disulfide in alkaline media give the corresponding carbodithioate salts. Heating of potassium 2-alkanoylhydrazinecarbodithioates with phenacyl bromide do not yield cyclization and failed to give the corresponding long-chain thiazolidine-2-thiones, but gave the corresponding 2-oxo-2-phenylethyl-2-alkanoylhydrazinecarbodithioates via nucleophilic substitution reaction. In addition, the synthesized compounds were tested for their corrosion prevention capabilities in acidic or in mineral oil media. Correspondence: Ayhan Yıldırım, Department of Chemistry, Faculty of Science and Arts, Uludağ University, 16059 Bursa, Turkey.     

Noncovalent organocatalytic synthesis of enantioenriched terminal aziridines with a quaternary stereogenic center

A high-yielding and enantioselective access to novel N-Boc terminal aziridines, bearing a quaternary stereogenic center, has been developed via an aza-Michael initiated ring-closure (aza-MIRC) reaction of α-acyl acrylates with an N-tosyloxy tert-butyl carbamate catalyzed by a chiral amino thiourea. The feasibility of the aziridine regioselective ring-opening to valuable α,α-disubstituted α-amino acid esters has been demonstrated.     

The preparation of 3,5-disubstituted tetrahydro-4H-1,3,5-oxadiazine-4-thiones,tetrahydro-4H-1,3,5-thiadiazin-4-ones,and tetrahydro-4H-1,3,5-thiadiazine-4-thiones

The reaction of 1,3-disubstituted thioureas with formaldehyde under acidic conditions with removal of water yielded 3,5-disubstituted tetrahydro-4H-1,3,5-oxadiazine-4-thiones. When hydrogen sulfide was bubbled through the reaction mixture, the corresponding tetrahydro-4H-1,3,5-thiadiazine-4-thiones were formed. Similarly, starting from 1,3-disubstituted ureas, a number of tetrahydro-4H-1,3,5-thiadiazine-4-ones were prepared. The latter compounds were also oxidized to the corresponding sulfoxides and sulfones.     

A study of the electrospray ionisation and ion-trap fragmentation of [M - H](-) ions of new 3,5-disubstituted tetrahydro-2H-1,3,5-thiadiazin-2-thiones

The electrospray ionisation (ESI) in negative mode of the pharmacologically significant 3,5-disubstituted tetrahydro-2H-1,3,5-thiadiazin-2-thiones, and their subsequent fragmentations using an ion-trap mass spectrometer, have been investigated. Experiments on sequential product ion fragmentations (MS(n)) were performed in order to elucidate the degradation pathways for these compounds. The data presented show that the fragmentation of the even-electron [M - H](-) ions could proceed through an internal nucleophilic substitution displacement. Decarboxylation and extrusion of carbon disulfide are other fragmentations observed.     

Reaction of dithiocarbamic acid salts with 4-substituted 2-thiolene- and 3,4-disubstituted thiolane 1,1-dioxides. Structural studies of N-phenylthiolano[3,4-d]thiazolidine-2-thione 5,5-dioxide

The reaction of monoalkyl(aryl)dithiocarbamic acid salts with 4-substituted 2-thiolene and 3,4-disubstituted thiolane 1,1-dioxides gave N-alkyl(aryl)thiolano-[3,4-d]thiazolidine-2-thione 5,5-dioxides, the structure of which was proved by x-ray diffraction studies. 1,1-Dioxothiol-3-en-3-yl esters were obtained with salts of dialkyl(heteryl)dithiocarbamic acids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 907–912, July, 1981.     

Solvent‐free One‐pot Synthesis of 2,2′‐dithioxo‐[5,5′]bithiazolidinylidene‐4,4′‐diones

Solvent‐free one‐pot synthesis of 2,2′‐dithioxo‐[5,5′]bithiazolidinylidene‐4,4′‐dione (birhodanine) derivatives from the reaction of primary amines and carbon disulfide in the presence of dimethyl acetylene dicarboxylate has been reported.     

Synthesis of spirooxindoles bearing 2,3-(or 2,5-)dihydrothiophene-2-thione moiety via [3+2] annulation of carbon disulfide with Morita-Baylis-Hillman carbonates of isatins

Various spirooxindoles bearing 2,3-(or 2,5-)dihydrothiophene-2-thione moiety have been synthesized via [3+2] annulation reaction of carbon disulfide and the nitrogen ylides derived from Morita-Baylis-Hillman carbonates of isatins. 2,3-Dihydro- and 2,5-dihydrothiophene-2-thione moieties were formed selectively depending on steric hindrance around the nitrogen ylides.     

Enolethers. XXI. Synthesis of 5,5′-disubstituted 4,4′-bipyrimidines

1,6-Dialkoxy-3,4-diones 3 are easily accessible by acylation of enol ethers 1 with oxalyl chloride and subsequent elimination of hydrogen chloride using triethylamine. The open-chain 2,5-dimethyl derivative 3b is converted with amidines 4a-c and S-methylisothiourea (4d) , respectively, to give 2,2′-disubstituted 5,5′-dimethyl-4,4′-bipyrimidines 5a-d . The dihydrofuran and dihydropyran derivatives 3c and 3d , however, react with benzamidine (4c) in dimethylformamide only in the presence of calcium hydride as condensation agent yielding 5,5′-bis(2-hydroxyethyl)- and 5,5′-bis(3-hydroxypropyl)-2,2′-diphenyl-4,4′-bipyrimidine 6a and b.     

One-pot synthesis of 1,4-dihydro-3,1-benzoxazine-2-thiones by the reaction of 2-lithiophenyl isothiocyanates with aldehydes or ketones

An efficient one-pot method for the synthesis of 4-monosubstituted and 4,4-disubstituted 1,4-dihydro-3,1-benzoxazine-2-thiones has been developed. Treatment of 2-bromophenyl isothiocyantes with butyllithium in THF at −78 °C generates 2-lithiophenyl isothiocyanates, which are allowed to react with various carbonyl compounds, including aldehydes, ketones, and butanolide, to give the corresponding desired products in moderate to good yields.