Sulfur monochloride, reaction with

An extensively studied and highly important 1,2,3-dithiazole - 4,5-dichloro-l,2, 3-dithiazol-l-ium chloride (Appel salt) 145 (R = Cl) - was first prepared by Appel and coworkers in 1985 by chlorination of chloroacetonitiile by sulfur monochloride in dichloromethane (1985CB1632) and it has been the most convenient procedure to date. Appel salt can be obtained also by prolonged chlorination of acetonitrile itself, or by the sulfur monochloride reaction with ethylamine the yields and experimental conditions were not disclosed (1985PS277). Recently, a series of mono-substituted acetonitriles were converted to 5-substituted-4-chloro-l,2,3-dithiazolium chlorides 145 (1999CC531,... 

Sulfur monochloride reacted with another titanocene complex 241 to give nonasulfur imide 242. The reaction proceeded smoothly at room temperature (1996AG(E)2537 Scheme 128). 

Yavolovskii et al. have reported the synthesis of several [l,2,5]selenadiazolo[3,4-rf pyrimidines (e.g., Scheme 77) and [l,2,5]thiadiazolo[3,4-<71pyrimidines (e.g., Scheme 73) using respective sulfur and selenium monochloride reactions with nitrosopyrimidinamines <2005RJC493>. 

Chivers and coworkers have reported that the reaction of sulfur monochloride, S2CI2 with Cl2P(NSiMe3)(NSiMe3)2 affords a material with a composition that is consistent with the polymer [SNPCUNJn (see Eq. 5.10) [3]. However, the discouraging solubility properties of this polymer did not allow its full characterization. 

Niobium Pent chloride. Niobium pentachloride can be prepared in a variety of ways but most easily by direct chlorination of niobium metal. The reaction takes place at 300—350°C. Chlorination of a niobium pentoxide—carbon mixture also yields the pentachloride however, generally the latter is contaminated with niobium oxide trichloride. The pentachloride is a lemon-yeUow crystalline soHd that melts to a red-orange Hquid and hydrolyzes readily to hydrochloric acid and niobic acid. It is soluble in concentrated hydrochloric and sulfuric acids, sulfur monochloride, and many organic solvents. 

Numerous organic reactions of sulfur monochloride are of practical and commercial importance. Of particular importance is the reaction of sulfur monochloride with olefins to yield various types of addition products (142). With ethylene, the severe vesicant bis(2-chloroethyl) sulfide [505-60-2] (mustard gas) forms with elemental sulfur and polysulfides (see Chemicals IN war). Propylene reacts similarly ... 

Sulfurized olefins (S2CI2 plus isobutene) are further reacted with S and Na2S to give products useful as extreme pressure lubricant additives (144,145). The reaction of unsaturated natural oils with sulfur monochloride gives resinous products known as Factice, which are useful as art-gum erasers and mbber additives (146,147). The addition reaction of sulfur monochloride with unsaturated polymers, eg, natural mbber, produces cross-links and thus serves as a means for vulcanizing mbber at moderate temperatures. The photochemical cross-linking of polyethylene has also been reported (148). 

The sulfur monochloride formed in this reaction can be treated with additional carbon disulfide in the presence of a catalyst to yield carbon tetrachloride and sulfur. Alternatively, the sulfur monochloride and carbon tetrachloride can be... 

Sulfur monochloride also reacts with substituted phenols to give condensation products useful for mbber compounding (qv) (150). Elf Atochem NA manufactures products known as Vultacs by the reaction of amylphenols and sulfur monochloride (153). 

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). 

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. 

The decomposition of sulfuryl chloride is accelerated by light and catalyzed by aluminum chloride and charcoal. Many of the reactions of sulfuryl chloride are explainable on the basis of its dissociation products. Sulfuryl chloride reacts with sulfur at 200°C or at ambient temperature in the presence of aluminum chloride producing sulfur monochloride. It hberates bromine or iodine from bromides or iodides. Sulfuryl chloride does not mix readily with water and hydrolyzes rather slowly. 

Arsenic trichloride (arsenic(III) chloride), AsQ. is the most common and important haUde of arsenic. It may be formed by spontaneous combination of the elements and, in addition, by the following reactions (/) chlorine with arsenic trioxide (2) sulfur monochloride, 82(11, or a mixture of S2CI2 chlorine, with arsenic trioxide and (J) arsenic trioxide with concentrated hydrochloric acid or with a mixture of sulfuric acid and a chloride. 

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). 

Sinclair (92) has described an improved method for the preparation of methyl 6-chloro-6-deoxy- -D-glucopyranoside (137) from methyl a-D-glucopyranoside (11). The reaction was effected with sulfur monochloride S2C12 in N,N-dimethylformamide at room temperature and the... 

Various other chemical agents which by their nature are capable of producing cross-linkages between polymer chains effect the same changes in physical properties that are observed in sulfur vulcanization. One of the best known of these agents is sulfur monochloride, which readily combines with two molecules of an olefin (the mustard gas reaction). Applied to rubber, it induces vulcanization even at moderate temperatures, the probable structure of the cross-linkage being... 

Thiadiazoles have proven of some utility as aromatic nuclei for medicinal agents. For example, the previous volume detailed the preparation of a series of "azolamide" diuretic agents based on this class of heterocycle. It is thus of note that the 1,2,5-thiadiazole ring provides the nucleus for a clinically useful agent for treatment of hypertension which operates by an entirely different mechanism, p-adrenergic blockade. In its preparation, reaction of the amide-nitrile 211 with sulfur monochloride leads directly to the substituted thiadiazole 212. ... 

Reaction of l-methyl-4-aminoimidazole (71 R1 = Me, R2 =H) with sulfur monochloride (S2C12) gave a product that was isolated and assumed to be the imidazo[4,5-c/]-l, 2,3-dithiazole (91) (56%) by analogy with other hetero-Herz reactions (84JOC1224). 

The reaction of methyl a-D-glucopyranoside with sulfur monochloride in N,N-dimethylformamide to give the 6-chloro-6-deoxy derivative in 30-35% yield has been described392 it is possible thatN,N-... 

Aminoacid amides are suitable synthons for transformation to 3-hydroxy-thiadiazoles 25 (1967JOC2823, 1984WOP8402525) in moderate yields (Scheme 14). Clycinamide gave 4-chloro-l,2,5-thiadiazol-3-ol (1993JPP05140133) in a reaction with sulfur monochloride. 

Cyanogen itself is reported to react smoothly with sulfur monochloride to form 3,4-dichloro-l,2,5-thiadiazole 37. The reaction was not exothermic and was readily run by passing cyanogens into an S2CI2 solution in dimethylformamide at 80 °C (1967JOC2823 Scheme 21). 

The reaction of a-dioximes with sulfur monochloride is usually complex and leads to a mixture of various heterocycles including 1,2,5-thiadiazoles, their Af-oxides 39 and sometimes 1,2,5-oxadiazoles (1967JOC2823, 1970JOC1165). Yields are low (Scheme 23). 

The reaction of 3-aminocinnamates 9 with sulfur monochloride leading to tetrasubstituted pyrroles 10 (see Section 2) can be stopped at the formation of 2H-l,4-thiazines 12 by the inverse addition of sulfur monochloride to compound 9. Yields of thiazines 12 may reach 58-77% (1984JOC4780 see Scheme 6). 

A series of five-membered heterocycles with two and three heteroatoms were synthesized. 4-Hydroxyisothiazoles 57 were prepared from a-amino ketones with sulfur monochloride (1968BCJ959). Polar solvents, especially N,Af-dimethylfor-mamide, were preferable (Scheme 28). In a similar reaction of 1-amino-l-phenyl-2-propanone with sulfur monochloride 5-chlorinated isothiazole 58 was obtained in high yield. 

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