Sulfur Monochloride Research Articles

Synthesis, Structure, and Some Reactions of (2,4,6-Tri-t-butyl)thiobenzaldehyde, the First Stable Aromatic Thioaldehyde

Abstract The title compound 1 was synthesized by the reaction of 2,4,6-tri-t-butylphenyllithium with O-ethyl thioformate or that of 2,4,6-tri-t-butylbenzaldehyde hydrazone with disulfur dichloride in the presence of triethylamine. The thioaldehyde 1 is a purple crystalline compound which is thermally quite stable; only around 200 °C it underwent intramolecular cyclization to give 6,8-di-t-butyl-3,4-dihydro-4,4-dimethyl-1H-2-benzothiopyran 9. The X-ray crystallographic analysis of 1 revealed that the thioformyl group is almost perpendicular to the aromatic ring. The reaction of 1 with 1-cyano-1-methylethyl radicals afforded 9, while that with t-butyl radicals gave 1,3,5-tri-t-butyl-2-t-butylthiomethylbenzene and t-butyl 2,2-dimethyl-1-(1,3,5-tri-t-butylbicyclo[2.2.0]hexa-2,5-dien-2-yl)propyl sulfide in addition to 9. Some Grignard reagents and organolithiums reacted with 1 gave carbophilic, thiophilic, double addition products and some others depending on the kind of the organometallic reagents. Hydrazine and butylamine reacted with 1 very readily to give the corresponding hydrazone and imine, respectively.

The oxidative coupling of coumaranone with disulfur dichloride

The reaction of 3(2 H)-benzofuranone ( 1) with S 2Cl 2 yields bis- 2-spirocoumaranoylidenetetrathiane ( 3) instead of oxindigo ( 2). The structure of 3 is established by X-ray crystal structure analysis.

Synthesis of amorphous poly(thioarylene)s via oxidative polymerization of diaryl disulfides

AbstractAmorphous poly(thioarylene)s containing a methyl substituent and/or an ether bond in the main chain were prepared via oxidative polymerization of diaryl disulfides using 2,3‐dichloro‐5,6‐dicyanobenzoquinone. The resulting poly(thio‐2,6‐dimethyl‐1,4‐phenyleneoxy‐1,4‐phenylene) having alternating ether and thioether bonds shows a better solvent solubility and has a higher glass transition temperature (Tg) (182°C) than non‐substituted poly(thio‐1,4‐phenylene). Polymerization of methyl substituted diphenyl ether derivatives with disulfur dichloride has been also developed for a one‐pot synthesis of amorphous poly(thioarylene)s.

New dithio-bis-(diaroylmethanes) and acetyl diaroylchloromethyl disulfides: Attractive synthons and precursors for the liberation of highly reactive dithiiranes or thiosulfines

In a new, feasible procedure five symmetricalpara-substituted diaroylmethanes ((4-X-C6H4-CO)2-CH2;X=F, Cl, Br, CH3, and CH3O) are prepared, in most cases in very good yields. For purification and activation, they are converted into the copper(II) complexes of their enolates. Subsequently, three reaction steps with disulfur dichloride (S2Cl2), chlorine, and ethanethioic acid yield new CH-acidic dithio-bis-(diaroylmethanes), α-chlorosulfenic acid chlorides, and acetyl diaroyl-chloromethyl disulfides. The latter compounds are of interest for the liberation of highly reactive dithiirane/thiosulfine species. With thiomorpholine, α-chlorosulfenic acid chlorides give α-chlorosulfenic acid amides.

Cyclopenta-1,2-dithioles, Cyclopenta-1,2-thiazines, and Methylenoindenes from New Molecular Rearrangements

The cyclobutanone oxime 6 reacts with disulfur dichloride, N-chlorosuccinimide, and Hünig's base to give three unexpected 10 π pseudoazulenes in low yield: the dark blue cyclopenta-1,2-dithiole 7, its red isomer 10, and the orange cyclopenta-1,2-thiazine 8. The benzo derivative 14 of oxime 6 gives an analogous benzo product 15 together with the methylenoindene 16 in high yield. The formation of all of these products can be explained by a unified mechanism based on initial abnormal Beckmann rearrangement of the oximes to cyanides followed by cyclization and/or exhaustive chlorination and dehydrochlorination. The 1,2-dithiole 7 is synthesized independently from 1-(cyanomethyl)cyclopentene 11 and the above reagents, and 1-cyanomethylindene 17 is similarly converted into methylenoindenes 18 and 19, which are isomers of product 16. Structures 7 and 15 are confirmed by X-ray crystallography, and compounds 7, 8, 15, 16, 18, and 19 show birefringence on heating in a hot stage polarizing microscope indicating, most unexpectedly, liquid crystalline behavior.

Cyclopenta-1,2-dithioles and cyclopenta-1,2-thiazines from new molecular rearrangements

The cyclobutanone oxime 6 reacts with disulfur dichloride to give two unexpected 10π pseudoazulenes in low yield: the dark blue cyclopenta-1,2-dithiole 7 and the orange cyclopenta-1,2-thiazine 8; the benzo derivative 14 of this oxime gives the analogous benzo product 15 together with the methylene indene 16 in high yield; mechanisms based on abnormal Beckman rearrangements are proposed for the formation of all of these products.

Tropothione S-Sulfide. A New Class of Thiosulfine

Abstract Tropothione S-sulfide is synthesized from tropone hydrazone with disulfur dichloride in deaerated chloroform at −78 °C. The S-sulfide is detected as an unprecedented [10π + 2π]-type cycloadduct with dimethyl acetylenedicarboxylate.

Photocrosslinking of polypropylene: the effect of different photo-initiators and coagents

Crosslinking of polypropylene (PP) induced by photoreduced (benzophenone. xanthone and 2-methyl anthraquinone) and photofragmentated (halogenated sulphur, phosphorus and hydrocarbon derivatives) substances was studied. It was found that high gel content could be obtained in PP using sulphur monochloride, sulphuryl chloride, trichlorethylene and tetrachlorethylene as photoinitiators. The gel yield in the presence of photoreduced initiators increases if acryloyloxy polyfunctional monomers are used as PP photocrosslinking promoters, whilst the effect of allylic monomers is comparatively small. Temperature increase was shown mainly to depress PP crosslinking efficiency and to enhance photothermal degradation, although increased gel yield was attained if PP containing photoreduced initiators combined with allylic monomers was exposed to UV light at temperatures up to 140 °C. DSC studies showed that the melting temperature and the heat of fusion of PP photocrosslinked in the molten state or recrystallized after crosslinking were decreased substantially with gel content, especially if photofragmented chlorides are used as initiators. Investigation of photocrosslinked PP tensile properties at ambient temperatures revealed the increase of Young's modulus and yield stress along with catastrophic decrease of strain at break. At increased testing temperatures ( T > 80 °C) the ductility of photocrosslinked PP is enhanced and its tensile properties noticeably surpass those of uncrosslinked samples.

A Convenient Approach to Benzopentathiepins. Application to the Synthesis of Varacin and Isolissoclinotoxin A Derivatives

Abstract The action of sulfur monochloride on aryl tert-butyl disulfides in tetrahydrofuran led directly to benzopentathiepins in good yields. The reaction was applied to the synthesis of two benzopentathiepins 10a and 10b, varacin 1 and isolissoclinotoxin A 2a derivatives.

Organic Heterocyclothiazenes. Part 19. Synthesis of 1,3,2-Dithiazoles Using Bis(chlorothiio)nitronium Tetrachloroaluminate, [N(SCl)2][AlCl4

Reaction of the readily prepared bis(chlorothio)nitronium tetrachloroaluminate (4) with electron-rich arylacetylenes in dichloromethane at room temperature leads to a cycloaddition reaction resulting in 4-aryl-1,3,2-dithiazolium salts (5) which when treated in situ with base afford 5-aryl-1,3,2-dithiazole-4-thiones (6). The scope of this reaction with other alkenes and alkynes is described. No reaction was observed with the electron-deficient 4nitrophenylacetylene. The conjugated thione (17) was also formed in the reaction of an old specimen of salt (4) with phenylacetylene. Treatment of salt (4) with 1,2-dichloroethylene followed by aniline gave a minor amount of the novel dimer (20). The reaction of acetophenone oxime with disulfur dichloride provides a route to the salt (26) which on treatment with water or aniline affords 4-phenyl-1,2,3-dithiazol-5-one (23) and 4-phenyl-5-phenylimino-1,2,3-dithiazole (27) respectively. 14 N NMR studies are shown to be useful in distinguishing between 1,2,3- and 1,3,2-dithiazoles. X-Ray crystal structures are presented for compounds (17,20,27), and 5-anilino-1,3,2-dithiazole-4-thione

Thermal polymerization of diaryl disulfides to yield poly(arylene sulfides)

The reaction of aromatic compounds and sulfur monochloride is investigated as a convenient route to prepare disulfides. Bis[4-[(4-bromophenyl)oxy]phenyl] disulfide (1), bis[4-[(4-bromophenyl)thio]-phenyl] disulfide (II), and bis-[[[(4-bromophenyl)sulfonyl]phenyl]oxy]phenyl] disulfide (III) were prepared through the electrophilic reaction of sulfur monochloride with aromatic compound catalyzed by SiO 2 . The thermal polymerization of the disulfide I results in the formation of high molecular weight poly(thio-1,4-phenyleneoxy-1,4-phenylene) (PPOS; M w =141 000) which is a high crystalline polymer with high stability after melting. The crystallographic data reveal that the resulting PPOS and poly(phenylene sulfide) both possess an orthorhombic unit cell

Organized polymerization of functional diblock copolymers possessing central isoprene groups

AbstractFunctional diblock copolymers possessing central isoprene groups were synthesized by anionic addition in a three‐stage process using styrene, isoprene, and 2‐vinylpyridine monomers. These diblock copolymers formed microphase‐separated structure in the solid state. Where the central isoprene groups are organized regularly at the domain interface of the microphase‐separated structure, this is due to the functional groups being located at the block junction position. Addition‐condensation of diblock copolymer film with sulfur monochloride formed AnBn star block copolymers by organization effects. © 1993 John Wiley & Sons, Inc.

Cyclopenta-1,2,3-dithiazoles and related compounds

Treatment of 3-phenylinden-1 -one oxime 6 with disulfur dichloride gives the indenodithiazole 2 directly in 58%; in the presence of Hunig's base the yield rises to 90%. Indenone oxime 9 and indanone oxime 11 with disulfur dichloride both give the chlorinated indenodithiazole 10, in up to 80% with Hunig's base. Similarly, cyclopentanone oxime gives the deeply violet trichlorocyclopentadithiazole 13(ca. 25%) at 4 °C in tetrahydrofuran with Hunig's base or in dimethylformamide without added base. A mechanism (see Scheme 1) is proposed for this extensive transformation in which a simple saturated oxime is converted into a highly functionalised heteroaromatic compound by the formation of 7 new bonds; this mechanism is based on the activation to chlorodeprotonation of all the cyclopentane positions, in turn, by the dithiazole ring. Analogously, cycloheptanone oxime 17 gives the red pentachlorocycloheptadithiazole 21, by the formation of 10 new bonds, and now di-, tri-, and tetrachloro intermediates, 18–20, can also be isolated; tetrahydrobenzocycloheptenone oxime 22 gives the analogous dichloro 23 and trichloro 24 compounds, and the acyclic oxime 25 gives the monocyclic dithiazole 27, all in modest yield. The chlorine in compound 10 is displaced by morpholine and pyrrolidine, but similar displacements in the trichloro compound 13 are unsuccessful since its heterocyclic ring is destroyed by nucleophiles. The pentachloro compound 21 is more stable than 13 towards nucleophiles, but less stable towards m-chloroperbenzoic acid, and these observations are explained in terms of the dipolar structures 13a and 21a.

Sulfur‐containing polymers by the reaction of diphenyl sulfide with sulfur chlorides

AbstractThe electrophilic reaction of sulfur dichloride with diphenyl sulfide proceeds efficiently at room temperature to yield oligo(phenylene sulfide) in the presence of a catalytic amount of Fe powder. Sulfur dichloride shows higher reactivity than sulfur monochloride. The reaction is promoted through the activation of sulfur dichloride by Fe powder. The polymeric product contains a linear structure linked by disulfide and sulfide bonds.

Selenium sulfur dihalides, ChnX2 (n = 1, 2, 3; Ch = Se, S; X = Br, Cl). Raman and 77Se NMR spectroscopic characterization

Solutions of Se2Cl2 in S2Cl2, Se2Br2 in S2Cl2, Se in S2Cl2, and S in Se2Cl2 have been studied by Raman and 77Se NMR spectroscopy. Selenium sulfur dihalides, SeSCl2, SeSBr2, and SeSBrCl, formed in these solutions, have been shown by Raman and 77Se NMR spectroscopy to have chain structures. Solutions of Se2Cl2 in S2Cl2, S in Se2Cl2, and Se in S2Cl2 have been shown to contain, in addition to Se2Cl2, S2Cl2, SeSCl2, Se3Cl2, and S8, trichalcogen dichlorides Se2SCl2 and SeS2Cl2. Selenium-77 signals corresponding to all seven chain isomers of the expected Se-containing dichalcogen dihalides, Se2Br2, Se2Cl2, Se2BrCl, SeSCl2, SeSBr2, BrSeSCl, and ClSeSBr, have been observed in the spectrum of a 1:1 molar mixture of S2Cl2 and Se2Br2. The disulfur dichloride and dibromide, as well as the bromide chloride, are also present. Selenium–bromine and sulphur–chlorine linkages are observed to be preferred over selenium–chlorine and sulphur–bromine bonding in these mixtures. The 77Se chemical shifts correlate well with the electronegativity of the directly bonded neighbour but inversely with that of the next-nearest neighbour. Keywords: selenium halides, sulfur halides, low valent chalcogen halides, 77Se NMR, Raman spectroscopy.

Thermo-oxidative stabilization of photochemically crosslinked polyethylene

Crosslinking efficiency and oxidative stability have been studied for a series of PE films containing different antioxidants as a function of exposure time and nature of photoinitiator. The striking difference between two groups of photoinitiators examined was demonstrated by comparing the oxidation induction periods of crosslinked samples. Crosslinking in the presence of sulfuryl chloride, phosphorus trichloride or phosphorus oxychloride results in dramatic decrease of the thermostability of the films, whilst using sulfur monochloride or thiophosphoryl chloride as the photoinitiator causes an initial drop of oxidation induction period which is followed by an increase after further UV irradiation. Thus photocrosslinking of PE can be accompanied by an increase of its thermostability in certain conditions.

Photolysis of Tetraalkyl‐1‐pyrazoline‐4‐thiones. – Diastereoselective Formation of ( E )/( Z )‐Alkylidenethiiranes from cis ‐ and trans ‐Tetraalkyl‐1‐pyrazoline‐4‐thiones

The tetraalkyl-1-pyrazolin-4-ones 5 react with hydrazine to afford the hydrazones 6 which are transformed into the thiones 7 in high yields by treatment with disulphur dichloride in the presence of triethylamine. Selective excitation of the azo chromophor of 7a with 350-nm light gives rise to the isopropylidenethiirane 8, besides molecular nitrogen, in a very clean reaction; at almost quantitative conversions, less than 2% of byproducts are observed, and about 10% of 8 have isomerized to the pentadienethiol 9. Photolysis of the stereoisomers cis- and trans-7b yields mixtures of the alkylidenethiiranes (E)-and (Z)-10 with (E)/(Z) ratios of 35:65 and 49:51. The results are interpreted in terms of diastereomeric bis-orthogonal (cis- and trans-21) and mono-orthogonal thioxyallyl diradicals (E)- and (Z)-23 which cyclize to furnish (E)- and (Z)-10. There seems to be a qualitative resemblance between the photochemical and thermal stabilities in the series of 4-substituted tetramethyl-1-pyrazolines, viz. 7a < 12 < 5a, 13, similar to that suggested by Engel for 2,3-diazabicyclo[2.2.2]oct-2-ene derivatives.

One-pot synthesis of poly(thioarylene)s: predominant sulphide bond formation through oxidative and electrophilic reaction

Poly(thioarylene)s are conveniently prepared in high yield at room temperature and atmospheric pressure through oxidative and electrophilic reaction of disulphur dichloride (S2Cl2) and aromatic compounds.

Stabilization of polyethylene films by photochemical crosslinking in the presence of sulphur monochloride and sulphuryl chloride

The authors have studied the thermal stability of LDP films crosslinked photochemically in presence of sulphur monochloride or sulphuryl chloride using as anti-oxidants Irganox 1076, Phenozan 23, FAU-13, Irganox B 225 and Diafen NN. It is shown that the presence of a photo-initiator substantially hastens the process of consumption of the anti-oxidants on exposure of the films to UV1light. The photoproducts formed ensure the practically unchanged thermal stability of the crosslinked samples for one year. With use as photo-initiator of sulphur monochloride the thermal stability of the film during crosslinking after a fall at the initial stage begins to rise and as a result materials may be obtained with a content 80–90% gel fractions characterized by an induction period not inferior to and indeed often exceeding several times the values for the unirradiated samples.

ChemInform Abstract: Synthesis of 1,1′‐Dibenzo‐ and 1,1′‐Dinaphtho‐2,2′‐dithiols from the Respective Thiophenes.

AbstractThe dibenzo‐ (Ia) or dinaphthothiophenes (Ib) are cleaved with lithium and then sulfurized with disulfur dichloride (II) to form the fused 1,2‐dithiins (III).