Sulfur dichlorides

Sulfur dichloride formed as a byproduct is converted to disulfur dichloride by adding excess sulfur. 

Applications Disulfur dichloride is utilized in the manufacture of sulfur dichloride, thionyl chloride and sulfur tetrafluoride and with polyols for the production of additives for high pressure lubricating oils and cutting oils. In addition it is used as a catalyst in the chlorination of acetic acid. Solutions of sulfur in disulfur dichloride is utilized in the room temperature vulcanization of rubbers. 

The worldwide consumption of disulfur dichloride has decreased from 30 10 t in 1987 to 15 10 t in 1992, due to a strong decrease in the consumption of chlorine-containing lubricants. 

Manufacture Sulfur dichloride is produced by reacting liquid disulfur dichloride with gaseous chlorine at low temperatures in the presence of catalysts e.g. iodine  

Since it is very unstable, decomposing into its starting materials, it is only produced as an intermediate product. 

Alkenes and alkynes react with sulfur dichloride (SC12), giving 2-chloroethyl(or vinyl)sulfenyl chlorides. The reaction is an electrophilic addition to the multiple bond, and consequently the possible intermediacy of thiiranes, or thiiranium ions analogous to bromonium ions, has been 

Hisano and Y. Yabuta, Chem. Pharm. Bull. 21, 511 (1973) F. Povazanec, B. Stanovnik, and M. Tisler, in Organic Sulphur Chemistry (C. J. M. Stirling, ed.), p. 420. Butterworth, London, 1975. 

Typical examples are the formation of 3-chloro-2-phenylbenzo[b]-thiophene (21) in near quantitative yield from diphenylacetylene at room temperature,27 and the synthesis of the dichlorothianonane (22) from 1,5-cyclooctadiene.28 

Muehlstaedt and co-workers have shown that similar sulfur bridges may be inserted into many other acyclic compounds typical products include benzoxathiins (23) and thiazolinones (24).29 

In the examples above the sulfur dichloride links together two carbon atoms. It is equally possible to link two nitrogen atoms, as illustrated by the formation of a 1,4,2,3,5,6-dithiatetrazine (25) from a hydrazodicarboxyl-ate ester.30 Amidinium salts afford 1,2,3,5-dithiazolium salts (26).31 

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Note 2. Sulfur dichloride was prepared by introducing the calculated amount of... 

C/760 mmHg) sulfur dichloride After the addition stirring v/as stopped and the flask was allowed to stand for 15 h in the ice-bath. The condenser was replaced with a drying tube containing CaCl (refluxing of the vinyl chloride had stopped completely after the addition of sulfur dichloride). 

Sulfur concrete Sulfur copolymers Sulfur cures Sulfur cure system Sulfur dichloride... 

Reaction with Sulfur Electrophiles. Bisa2iridine compounds can be prepared from sulfur dichloride, thionyl chloride, or sulfuryl chloride... 

Methylphenol is converted to 6-/ f2 -butyl-2-methylphenol [2219-82-1] by alkylation with isobutylene under aluminum catalysis. A number of phenoHc anti-oxidants used to stabilize mbber and plastics against thermal oxidative degradation are based on this compound. The condensation of 6-/ f2 -butyl-2-methylphenol with formaldehyde yields 4,4 -methylenebis(2-methyl-6-/ f2 butylphenol) [96-65-17, reaction with sulfur dichloride yields 4,4 -thiobis(2-methyl-6-/ f2 butylphenol) [96-66-2] and reaction with methyl acrylate under base catalysis yields the corresponding hydrocinnamate. Transesterification of the hydrocinnamate with triethylene glycol yields triethylene glycol-bis[3-(3-/ f2 -butyl-5-methyl-4-hydroxyphenyl)propionate] [36443-68-2] (39). 2-Methylphenol is also a component of cresyHc acids, blends of phenol, cresols, and xylenols. CresyHc acids are used as solvents in a number of coating appHcations (see Table 3). 

The bulk of 4-methylphenol is used in the production of phenoHc antioxidants. The alkylation of 4-methylphenol with isobutylene under acid catalysis yields 2-/ f2 -butyl-4-methylphenol [2409-55-4] and 2,6-di-/ f2 -butyl-4-methylphenol [128-37-0]. The former condenses with formaldehyde under acid catalysis to yield 2,2 -methylene bis(6-/ f2 -butyl-4-methylphenol) [119-47-1], which is widely used in the stabilization of natural and synthetic mbber (43). The reaction of 2-/ l -butyl-4-methylphenol with sulfur dichloride yields 2,2 -thiobis(6-/ l -butyl-4-methylphenol) [90-66-4]. 

Another use of 4-/ f2 octylphenol is ia the productioa of uv stabilizers. 4-/ f2 -Octylpheaol reacts with sulfur dichloride to yield the thio-hisphenol derivative, which thea reacts with nickel acetate to form 2,2 -thiobis(4-/ f2 octylphenolate)-A/-butylamiQe nickel [14516-71 -3]. This type of stabilizer is widely used in the production of outdoor carpeting based on polypropylene fibers. Nickel compounds give a green discoloration which limits their apphcatioas. A second class of uv stabilizers based on the benzotriazole stmcture. 2-(2 -hydroxy-5 -/ f2 octylphenyl)benzotriazole [3147-75-9] is produced from 4-/ i -octylphenol (55). 

Carbonyl sulfide reacts with chlorine forming phosgene (qv) and sulfur dichloride [10545-99-0] and with ammonia forming urea and ammonium sulfide [12135-76-1]. Carbonyl sulfide attacks metals, eg, copper, ia the presence of moisture and is thought to be iavolved ia atmospheric sulfur corrosion (27,28). Its presence ia propane gas at levels above a few ppm may cause the gas to fail the copper-corrosion test. 

The solubihty of sulfur dichloride ia water is not meaningflil because it reacts rapidly. It is slightly soluble ia aUphatic hydrocarbons and very soluble ia benzene and carbon tetrachloride. The heat of formation is —22 kJ/mol (—5.3 kcal/mol) for the gas at 25°C (138). 

Chemical Properties. Sulfur dichloride ia the Hquid state at ambient temperature is ia equiHbrium with sulfur monochloride and dissolved... 

The equiHbrium constant is 0.013 at 18°C. Sulfur dichloride reacts violently with water, forming hydrogen chloride, sulfur dioxide, hydrogen sulfide, sulfur, and a mixture of thionic acids. 

Sulfur dichloride is oxidized by sulfur trioxide or chlorosulfuric acid [7790-94-5] (qv) to form thionyl chloride ... 

Economic Aspects. The price of sulfur dichloride was 0.26 /kg bulk ia 1995. Akzo Nobel is the only U.S. producer with merchant sales. Whereas some companies stiH produce sulfur dichloride for captive use (158), Occidental Chemical Company ended sulfur dichloride production ialate 1993. 

Chemical Reactions. Sulfur dichloride reacts with an excess of sulfur trioxide forming pyrosulfuryl chloride ... 

Sulfur dichloride undergoes many of the same reactions with organic compounds as described for sulfur monochloride. Addition to olefins affords a route to bis(2-chloroalkyl) sulfides and, ia certain cases, heterocycHc sulfides (159,160). 

Sulfur dichloride reacts with hexafluoropropene ia the presence of fluorosulfonic acid at 30—60°C to give the foUowiag (161) ... 

Manufacture. The manufacture of sulfur dichloride is similar to that of sulfur monochloride, except that the last stage of chlorination proceeds slowly and must be conducted at temperatures below 40°C. The preparation of a high assay sulfur dichloride requites special techniques, eg, continuous chlorination duriag distillation or distillation with traces of phosphoms trichloride or phosphoms pentasulfide [1314-80-3] (162—164). Cmde product containing 80 wt % sulfur dichloride to which is added 0.1 wt % phosphoms trichloride can be distilled to yield a 98—99 wt % pure sulfur dichloride, which can be stored for weeks at room temperature without appreciable change. 

Shipment and Storage. Sulfur dichloride, if kept dry, is noncorrosive at ambient temperatures, thus carbon steel and Hon can be used Hi the constmction of tanks, piping, and dmms. However, when water or humidity is present, materials resistant to hydrochloric acid must be used, eg, glass-lined pipe. Teflon, titanium, HasteUoy C, or possibly a chemically resistant, glass-reiaforced polyester. Threaded pipe joHits should be assembled with Teflon tape. Hoses should be constmcted with a Teflon inner lining with the outer tube constmcted of Neoprene or braided 316 stainless steel protected by an adequate thickness of Teflon. Sulfur dichloride should be stored away from heat and away from dHect rays of the sum. Toluene and sulfur dichloride react exothermically when catalyzed by Hon or ferric chloride. Safety precautions should be foUowed when such a mixture is present (165). 

Uses. Sulfur dichloride is used as a chlorinating agent Hi the manufacture of parathion [56-38-2] Hisecticide Hitermediates (see Insect control technology) ... 

An insecticide intermediate, 4,4 -thiobisphenol [2664-63-3] is made from sulfur dichloride and phenol ... 

Antioxidants used in lubricants are also made by reaction of sulfur dichloride with phenols ... 

The sulfur dichloride can be fed as such or produced directiy in the reactor by reaction of chlorine with sulfur monochloride. 

In a batch process (176), a glass-lined jacketed iron vessel is charged with either sulfur monochloride or sulfur dichloride and about 1% of antimony trichloride as a catalyst. Chlorine is introduced into the reactor near the bottom. Liquid oleum is added to the reactor at such a rate that the temperature of the reaction mass is held at ca 25°C by the use of cooling water in the jacket. 

At present, thionyl chloride is produced commercially by the continuous reaction of sulfur dioxide (or sulfur trioxide) with sulfur monochloride (or sulfur dichloride) mixed with excess chlorine. The reaction is conducted in the gaseous phase at elevated temperature over activated carbon (178). Unreacted sulfur dioxide is mixed with the stoichiometric amount of chlorine and allowed to react at low temperature over activated carbon to form sulfuryl chloride, which is fed back to the main thionyl chloride reactor. 

A number of processes have been devised for purifying thionyl chloride. A recommended laboratory method involves distillation from quinoline and boiled linseed oil. Commercial processes involve adding various high boiling olefins such as styrene (qv) to react with the sulfur chlorides to form adducts that remain in the distillation residue when the thionyl chloride is redistilled (179). Alternatively, sulfur can be fed into the top of the distillation column to react with the sulfur dichloride (180). Commercial thionyl chloride has a purity of 98—99.6% minimum, having sulfur dioxide, sulfur chlorides, and sulfuryl chloride as possible impurities. These can be determined by gas chromatography (181). 

Sulfur monochloride [10025-67-9] S2CI2, and sulfur dichloride,SCl2, react with unsaturated materials, forming products that are cross-linked by sulfur but which also contain chlorine (eq. 7) (10). 

The direct formation of dipyrimidin-5-yl sulfides occurs on treatment of appropriate 5-unsubstituted pyrimidine substrates with sulfur mono- or di-chloride. Thus, reaction of uracil (83 R = H) with sulfur monochloride in boiling formic acid gives diuracil-5-yl sulfide in good yield sulfur dichloride gives a poor yield. Simple derivatives of uracil and barbituric acid undergo similar reactions but not cytosine, isocytosine, 2,4-bismethylthiopyrimidine or pyrimidine-4,6-dione (59). The mechanism is unknown (72AJC2275). 

Chloroethyldisulfides are obtained by electrophilic attack on the sulfur atom of thiiranes by sulfenyl halides (Scheme 39). Sulfur dichloride and disulfur dichloride react similarly to give more sulfur-rich derivatives di- and tri-sulfenyl halides, and tri- and tetra-sulfides (Scheme 42). A 1 1 ratio of sulfur halide to thiirane gives the di- or tri-sulfenyl halide a 2 1 ratio the tri- or tetra-sulfide. Thiirane 1-oxides are cleaved by sulfenyl halides to thiolsulfinates (Scheme 43) (74JAP7440461). 

Diphenyl sulfide can best be prepared by treating benzene and aluminum chloride with sulfur chloride, sulfur dichloride, or sulfur. In addition to diphenyl sulfide there are found traces of thiophenol and varying amounts of thianthrene. 

The method of synthesis described for chloropyruvic acid is essentially that reported. This procedure affords the product in excellent yields from readily available materials by a short, convenient route. Other less acceptable methods involve chlorination of pyruvic acid with sulfur dichloride or hypochlorous acid and the treatment of ethyl chloro(l-hydroxyheptyl)- or (o -hydroxybenzyl)oxalacetate 7-lactone with 50% hydrochloric acid. ... 

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