Intramolecular Thiiranocyclobutane-Open Chain Isomerization of 3,3'-Dithioxo Sulfide Derivatives: A Quantum-Chemical Study

The thermodynamic stability and structural and electronic characteristics of thiabicyclic structures, expected products of photochemical isomerization of bis(3-thioxo-1-phenylpropenyl), bis(3-thioxo-1-propenyl), and bis(5,5-dimethyl-3-thioxocyclohex-1-enyl) sulfides, were evaluated by quantum-chemical calculations. The energy in the thiabicyclic structures is accumulated owing to formation of metastable highly strained fused systems. The heats of dark isomerization of thiabicyclic structures into acyclic ones range from 50 to 250 kJ mol^{- 1}. The activation energy of thermal transformations into acyclic isomers are 90-310 kJ mol^{- 1}. Higher thermal effects and lower activation energies are obtained when the polarity of the medium is taken into account. The calculation results show that this class of compounds is promising for solar energy conversion.     

Steric Structure of Bis(5,5-dimethyl-3-thioxo-1-cyclohexenyl) Sulfide

Two-dimensional NMR spectroscopy, dipole moment measurements, and quantum-chemical calculations (basis 6-31G^*) were used to show that in the gas phase and in solutions bis(5,5-dimethyl-3-thioxo-1-cyclohexenyl) sulfide prefers a nonplanar cis-trans conformation.     

Hydrolysis of Bis[5,5-dimethyl-3-(4-oxa-1-azoniacyclohexylidene)-1-cyclohexenyl] Sulfide Diperchlorate

Hydrolysis of bis[5,5-dimethyl-3-(4-oxa-1-azoniacyclohexylidene)-1-cyclohexenyl] sulfide diperchlorate, as well as of bis(5,5-dimethyl-3-thioxo-1-cyclohexenyl) sulfide, in the system MeCN-Et₃N yields a mixture of bis(5,5-dimethyl-3-oxo-1-cyclohexenyl) sulfide and isomeric 5,5-dimethyl-3-oxo-1-cyclohexenyl 3,3-dimethyl-5-oxo-1-cyclohexenyl sulfide. The structure of the products and their ratio were established by ¹H and ¹³C NMR and IR spectroscopy.     

1,7-Dithioxo Systems. Synthetic Routes to Bis(5,5-dimethyl-3-thioxo-1-cyclohexenyl) Sulfide

Synthetic routes to bis(5,5-dimethyl-3-thioxo-1-cyclohexenyl) sulfide have been studied. The title compound can be obtained by reaction of 3-chloro-5,5-dimethyl-2-cyclohexenethione with sodium thiosulfate and by condensation of 3-mercapto-5,5-dimethyl-2-cyclohexenethione. The reaction of bis(5,5-dimethyl-3-oxo-1-cyclohexenyl) sulfide with hydrogen sulfide and hydrogen chloride yields 3-oxo-3'-thioxobis(5,5-dimethyl-1-cyclohexenyl) sulfide.     

Preparation, structure and coordination properties of 3,3-bis(diisopropylamino)-3-thioxo-1-(2,4,6-tri-tert-butylphenyl)-1,3- diphosphapropene

(Z)-1-Chloro-2-(2,4,6-tri-tert-butylphenyl)-2-phosphaethenyllithium was allowed to react with bis(diisopropylamino)-phosphenium triflate to afford the corresponding 1,3-diphosphapropene which was converted to 3-thioxo-1,3-diphosphapropene [(Z)-Mes*P = C(Cl)-P(= S)(NiPr2)2]. The coordination properties of 3-thioxo-1,3'-diphosphapropene were investigated with carbonyltungsten(0) and dichloroplatinum(II) reagents, and the molecular structure of the chelate dichloroplatinum(II) complex was unambiguously determined by X-ray crystallography together with the free ligand. The dichloroplatinum(II) complex underwent intramolecular cyclisation involving C-H activation to give a 5,7-di-tert-butyl-3,3-dimethyl-l-(phosphinomethyl)-1-phosphaindane derivative as well.     

Synthesis and structure of a new heterocyclic system – 7,8-dihydroimidazo- [1,2-<Emphasis Type="Italic">c</Emphasis>][1,3]thiazolo[4,5-<Emphasis Type="Italic">e</Emphasis>]pyrimidine

The purpose-directed synthesis of a new heterocyclic system, 7,8-dihydroimidazo[1,2-c][1,3]thia- zolo[4,5-e]pyrimidine has been carried out based on the successive interaction of available 2-(aroyl- aminocyanomethylene)imidazolidines with hydrogen sulfide and triethyl orthoformate with subsequent intramolecular cyclocondensation of the obtained 8-aroylamino-7-thioxo-1,2,3,7-tetrahydroimidazo- [1,2-c]pyrimidines under the action of phosphorus pentasulfide or polyphosphoric acid.     

One-pot,Simple, and Convenient Synthesis of 2-Thioxo-2,3-dihydroquinazolin-4(1<Emphasis Type="Italic">H</Emphasis>)-ones

Summary. A simple and convenient method for the synthesis of diverse 2-thioxo-2,3-dihydroquinazolin-4(1H)-ones was developed as one-pot reaction of anthranilic acid esters, primary amines, and bis(benzotriazolyl)methanethione in presence of the amidine base DBU.     

One-pot, Simple, and Convenient Synthesis of 2-Thioxo-2,3-dihydroquinazolin-4(1 H )-ones

A simple and convenient method for the synthesis of diverse 2-thioxo-2,3-dihydroquinazolin-4(1H)-ones was developed as one-pot reaction of anthranilic acid esters, primary amines, and bis(benzotriazolyl)methanethione in presence of the amidine base DBU.     

Eco-friendly rapid synthesis of 3-substituted-2-thioxo-2,3-dihydroquinazolin-4(1H)-ones in choline chloride based deep eutectic solvent

A series of 3-substituted-2-thioxo-2,3-dihydroquinazolin-4(1H)-ones and 6-iodo-3-substituted-2-thioxo-2,3-dihydroquinazolin-4(1H)-ones were synthesized in choline chloride/urea deep eutectic solvent. Substituted 2-mercapto-4(3H)-quinazolinones were synthesized from anthranilic acid or 5-iodoanthranilic acid and appropriate isothiocyanates in good to excellent yields. Isolation of final product was easy and required no further purification. Synthesis of these compounds was rapid, selective, and catalyst free, while preparation of deep eutectic solvent was easy, components are readily available, cheap, and environmentally friendly.     

1,7-Dithioxo systems. Photochemical, thermal, and chemical stabilities of bis(5,5-dimethyl-3-thioxo-1-cyclohexenyl) sulfide

Photochemical, thermal, and chemical stabilities of bis(5,5-dimethyl-3-thioxo-1-cyclohexenyl) sulfide in crystal and in solution were studied.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 10, 2004, pp. 1692–1694.Original Russian Text Copyright © 2004 by Timokhina, Panova, Kanitskaya, Sokolnikova, Voronkov.This revised version was published online in April 2005 with a corrected cover date.     

Facile and convenient synthesis of new thieno[2,3-b]-thiophene derivatives

A facile and convenient synthesis of bis(2-(1H-benzo[d]imidazol-2(3H)-ylidene)-3-oxopropanenitrile), bis((3-amino-5-(methylthio)-1H-pyrazol-4-yl)methanone) and bis(2-thioxo-1,2-dihydropyrimidine-5-carbonitrile) derivatives incorporating a thieno- [2,3-b]thiophene moiety via versatile, readily accessible diethyl 3,4-dimethylthieno-[2,3-b]thiophene-2,5-dicarboxylate is described.     

Quantum-chemical study of intramolecular photocyclization in bis(thioxopropenyl) sulfide systems

Principal possibility of formation of trithiatetracyclononane structures via intramolecular rearrangements in bis(thioxopropenyl) sulfide systems, involving the lowest triplet state, was studied by the DFT(B3LYP) quantum-chemical molecular modeling analysis.     

Hydrothiolysis of carbofunctional α,β-unsaturated sulfides as an approach to the synthesis of 1,7-dithiocarbonyl compounds

Bis(1-N,N-dimethylimmonio-3-phenylprop-2-en-3-yl) sulfide diperchlorate and (1-N,N-dimethyl-immonio-3-phenylprop-2-en-3-yl) (5,5-dimethyl-1-morpholiniocyclohex-2-en-3-yl) sulfide diperchlorate react with hydrogen sulfide giving rise to the corresponding 1,7-thioxoimmonio sulfides. Treating with the hydrogen sulfide (1-N,N-dimethylimmonio-3-phenylprop-2-en-3-yl) (1-oxo-2-phenyl-inden-3-yl) sulfide perchlorate led to preparation of (1-oxo-2-phenylinden-3-yl) (1-thioxo-3-phenylprop-2-en-3-yl) sulfide. The hydrothiolysis of (5,5-dimethyl-1-morpholiniocyclohex-2-en-3-yl) (1-N,N-dimethylimmonio-2-phenylinden-3-yl) sulfide diperchlorate and (5,5-dimethyl-1-morpholiniocyclohex-2-en-3-yl) (1-oxo-2-phenylinden-3-yl) sulfidea perchlorate resulted in products of the sulfide bond cleavage in the initial immonium salts.     

Synthesis of new purine,pteridine, and other pyrimidine derivatives

The reaction of malononitrile dimer with phenyl isothiocyanate gave (6-amino-1-phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidin-4-ylidene)malononitrile which was then used as starting material in the synthesis of pharmacologically important fused pyrimidine derivatives, such as 4-dicyanomethylidene-1,5-diphenyl-2-thioxo-1,2,3,4-tetrahydropyrrolo[2,3-d]pyrimidine, 6-cyano-4-dicyanomethylidene-7-methylsulfanyl-5-oxo-1-phenyl-2-thioxo-1,2,3,4,5,8-hexahydropyrido[2,3-d]pyrimidine, 6-dicyanomethylidene-3-phenyl-2-thioxo-1,2,3,6-tetrahydro-9H-purine, and 6-substituted 4-dicyanomethylidene-7-oxo-1-phenyl-2-thioxo-1,2,3,4,7,8-hexahydropteridines. Published in Russian in Zhurnal Organicheskoi Khimii, 2007, Vol. 43, No. 3, pp. 443–449. The text was submitted by the authors in English.     

Synthesis and biological activity of some 1,3,2-diheteraphosphorinanes and their acyclic analogs

Methods were developed for the synthesis of 2-butylthio-2-oxo-1,3,2-oxazaphosphorinane, 2-butylthio-2-thioxo-1,3,2-dioxaphosphorinane, and 2-butylthio-2-thioxo-1,3,2-diazaphosphorinane, as well as of acyclicS-butylO-ethyl (diethylamido)phosphorothioates and-dithioates andS-butyl bis(diethylamido)phosphorodithioate. These compounds can serve as models of possible metabolites of cyclic compounds. Based on the data obtained in studies of the antiesterase activity of the resulting compounds and their synergistic activity in mixtures with permethrine, a possible mechanism ofin vitro andin vivo biological action of diheteraphosphorinanes was proposed.     

3-Arylazo-2-thioxo-2,3-dihydro-1<Emphasis Type="Italic">H</Emphasis>-quinazolin-4-ones as Azodisperse Dyes for Dyeing Polyester Fabrics

Summary. Diazotized 3-amino-2-thioxo-2,3-dihydro-1H-quinazolin-4-one was coupled with various hydroxy aromatics to give the corresponding 3-arylazo-2-thioxo-2,3-dihydro-1H-quinazolin-4-ones in reasonable yields. The dyes produced were applied to polyesters as disperse dyes and their fastness properties were elevated.     

Aromatic Ring Strain in Arylselenenyl Bromides: Role in Facile Synthesis of Selenenate Esters via Intramolecular Cyclization

The synthesis and reactivity of 2,6‐disubstituted arylselenium compounds derived from 2‐bromo‐5‐tert‐butylisophthalic acid ( 43 ) are described. The syntheses of bis(5‐tert‐butylisophthalic acid dimethyl ester)diselenide ( 46 ) and bis(5‐tert‐butylisophthalic acid diisopropyl ester)diselenide ( 47 ) have been achieved by the reaction of the corresponding ester precursors with disodium diselenide. Reduction of diselenide 46 with lithium aluminum hydride affords 2,2′‐bis(5‐tert‐butylbenzene‐1,3‐dimethanol)diselenide ( 53 ). Diselenides 46 and 47 exhibit intramolecular Se???O interaction. Compound 53 does not show any intramolecular Se???O interaction. The anomalous Se???O nonbonded coordination observed in the single‐crystal X‐ray structures of compounds 46 , 47 and 53 is compared and contrasted. The corresponding selenenyl bromides 54 and 55 , derived from the reaction of diselenides 46 and 47 with bromine, are quite stable in the solid state. However, they undergo hydrolysis and subsequent intramolecular cyclization upon heating or after having been kept in solution over a period of time to give the corresponding selenenate esters 56 and 57 . The X‐ray crystallographic study and density functional theory calculations on 54 at the B3LYP/6‐31G(d) level of theory indicate a significant distortion in planarity of the aromatic ring. Glutathione peroxidase‐like activities of diselenides 46 and 47 and their selenenate esters 56 and 57 have been studied both by thiophenol and bioassay methods. The very low glutathione peroxidase‐like activity of the diselenides ( 46 and 47 ) and their selenenate esters ( 56 and 57 ) in the thiophenol assay is attributed to the presence of the relatively strong Se???O intramolecular interaction in the selenenyl sulfide intermediates. The interaction retards the catalytic activity through both thiol exchange and an intramolecular cyclization reaction.     

Dynamic 1H NMR spectroscopy of η2-ethylene transition metal complexes

The low-temperature ¹H NMR spectra of bis(ethylene)trimethylphosphinenickel (1), η⁵-cyclopentadienyl(ethylene)methylnickel (2a), bis(ethylene)-η⁵-cyclopentadienylcobalt (2b), [bis(1-ethyl-2,4,6-triphenylphosphorinyl)nickel]P,P′-nickel(ethylene) (3) and η⁵-cyclopentadienyl(ethylene)hydrido(triphenylphosphine)ruthenium (4) exhibit {AA′B′B} (1) {ABB′A} (2a and 2b), {ABA′B′} (3) or {ABCD} (4) spin patterns, respectively, for the complexed ethylene. A full line shape analysis including all the proton couplings was performed for the ethylene rotation in 1, 2a and 2b. In addition to olefin rotation, a reversible intramolecular β-H-elimination was confirmed for 4 by magnetization transfer experiments.     

1H and 13C NMR spectral assignment of alkyl and polyamine-linked bis(2-thioxo-[1,3,5]-thiadiazinan-3-yl) carboxylic acids

The 1H and 13C NMR spectroscopic data for alkyl and polyamine-linked bis(2-thioxo-[1,3,5]thiadiazinan-3-yl) carboxylic acids, prepared from alkyl diamines and N4-(benzyl) spermidine have been fully assigned by combination of one- and two-dimensional experiments (DEPT, HMBC, HMQC, COSY).     

Utilization of Dipotassium Salt of Galactaric Acid Bis(Hydrazidocarbodithioic Acid) As a Synthone for Double-Headed 1,3,4-Thiadiazoline, 1,3,4-Oxadiazoline and 1,2,4-Triazoline Acyclo C-Nucleosides

Condensation of galactaric acid bis hydrazide (1) with carbon disulfide in the presence of ethanolic potassium hydroxide gave the dipotassium salt of galactaric acid bis (hydrazidocarbodithioic acid) (2). Heterocyclization of the key compound 2 produced three different types of double headed acyclo C-nucleosides: acid-catalyzed dehydrative cyclization afforded the 5-thioxo-1,3,4-thiadiazoline 3, base-catalyzed dehydrosulfurative cyclization gave the 5-thioxo-1,3,4-oxadiazoline 5, and condensative cyclization with concomitant dehydrosulfuration and dehydration with different nitrogen nucleophiles yielded the 5-thioxo-1,2,4-triazolines 7 and 9a, b. Acetylation of the prepared acyclo C-nucleosides 3, 5, 7 and 9a, b with acetic anhydride in the presence of pyridine at ambient temperature caused acetylation of the sugar hydroxyls as well as heterocyclo imino protons to give the tetra-O-acetates 4, 6, and 10a, b, respectively. Representative members of the prepared compounds were tested for antimicrobial activity.