Sulphuryl halides

Sulphur(Vl) forms the oxide chloride S02C12, sulphuryl chloride see sulphuryl halides). 

Details of the structures of the pyramidal molecules of thionyl halides (SOX2) and SeOF2 and of the tetrahedral molecules of sulphuryl halides (SO2X2), which have been studied as gases, are included in Tables 16.3 and 16.4. The structures of SeOCl2 (and also SeOF2) have been determined in a number of adducts (p. 600). 

Sulphonyl halides, mainly the chlorides, may be prepared using halosulphonic acids, sulphur dioxide and sulphuryl halides as the most important sources of sulphur. These preparative methods are discussed below. 

Sulphuryl halides may be used as reagents in the formation of sulphonyl halides from aromatics, alkenes or alkyl halides. The reaction usually proceeds via a radical mechanism, in the presence of a base (which removes HC1 generated in the reaction). If DMF is used as a solvent, yields are often improved534,535. 

The mean vibrational amplitudes of simple sulphuryl halides as determined from electron diffraction and calculated from spectroscopic data are collected in Table 4. 

Some imidoyl halides have been used to effect amide-bond formation between acids and primary amines. Owing to the highly selective nature of the reagents, peptides can be obtained from unprotected a-amino-acids although, if possible, it is best to protect the amino group of the first amino-acid. The sulphuryl halide SO2CIF can also be used to directly couple acids and amines, under mild conditions. ... 

Fundamental information on bonding is provided by photoelectron spectroscopy of thioanisoles and other alkyl aryl sulphides. Two conformers are predominant for these compounds, RSPh, and the proportion of the conformer with maximum overlap decreases through the series R = H, Me, Et, Pr or Bu. Related studies for sulphoxides provide correlation diagrams for the effects of substituents R in RS(0)R, as well as information on preferred conformations. An orienting survey of hexavalent sulphur functional groups, viz. alkyl, vinyl, and aryl sulphones, S -dialkyl sulphimides, sulphuryl halides, sulphoximides, and sulphurdi-imides, is available. ... 

When there is no diluent, organic acid chlorides and metal halides react very violently with DMSO. This goes for acetyl chloride, benzenesulphonyl (C6H5SO2CI), cyanuryl chloride, phosphorus and phosphoryl trichlorides, tetrachlorosilane, sulphur, thionyl, and sulphuryl chlorides. With oxalyl chloride, the reaction is explosive at ambient temperature, but can be controlled at -60°C in a solution with dichloromethane. The dangerous reactions are thought to be... 

The vanadium tetrachloride distils over and is purified from any ferric chloride present either by distillation or by extraction of the product with carbon tetrachloride, in which only the vanadium halide is soluble.2 Sulphuryl chloride, thionyl chloride, sulphur monochloride, and phosgene can all be used in the last reaction instead of chlorine, and the ferrovanadium also can be substituted by vanadium carbide, V4C3,3 nitride, VN,4 subsilicide, V2Si,5 disilicide, VSi2,8 or pentoxide.7... 

The hexahalides are kinetically inert, but most other halides are highly reactive and are hydrolised in water giving oxides and oxoacids. Intermediate hydrolysis products are oxohalides of which thionyl chloride SOCl2 and sulphuryl chloride S02C12 are industrially important compounds. 

Dialkylsulphamoyl (264) and monoalkylsulphamoyl (265) halides have been prepared by the reaction of amines or amine hydrochlorides with sulphuryl chloride (equation 80)264-269. Sulphuryl chloride also reacts with dialkylsulphamides to give sulphamoyl halides 266 (equation 81)270. 

The attempted direct chlorination of compounds 358, 359 and 360 resulted in tarring. However, a reaction with sulphuryl chloride in acetic acid afforded 7-chloro derivatives 361, 364 and 367 in 4—90% yields. lodination of the same bases occurred quite easily on treating them with iodine in aqueous alkali to form iodo derivatives 363, 366 and 369 (60-88%). Substitution occurs in the 7th position of the IcP molecule, as in the case of chlorination and bromination. In the PMR spectra of all halides 361-369, only a singlet of 6-H at 7.77—7.91 ppm (in CF3COOH) appears (94KG1076). Bromination of 4-ethoxy-l,3-dimethyl-IcP-2-one (371) proceeds very easily to give its 7-bromo derivative 372 in 87% yield. This compound was also obtained when nitro compound 357 was treated with ethanolic alkali (94KG1076). 

Direct oxidation of chloridites (6.320), the action of chlorine or sulphuryl chloride on trialkyl phosphites (6.349) or on dialkyl phosphonales (5.335) can be employed. A method of historical interest is to heat a silver phosphorofluoridate with an alkyl halide (5.336). A halophosphate is also obtained by reacting a pyrophosphoryl halide with ethanol at low temperature (5.337). 

Phosphonyl halides may be obtained from the phosphonous halide by oxidation with sulphuryl chloride, nitrogen dioxide or oxygen (6.184). With some compounds direct oxidation of a solution may be effected with blown air (6.185). 

Direct addition can be used to obtain other derivatives (9.660) and (9.661), while halides can be obtained from these with sulphuryl chloride (9.662). 

According to the different donor properties found in this group of solvents a distinction may be made between (a) oxyhalides with low donor numbers including carbonyl chloride, nitrosyl chloride, thionyl chloride, sulphuryl chloride, acetyl and benzoyl halides and (b) oxyhalides with medium donor numbers, namely phosphorus oxychloride, selenium oxychloride and phenyl phosphonic halides, the latter having donor properties approaching those of water or of the ethers. 

Among other reagents causing fission of tin-carbon bonds are hydrogen halides, mercury halides, bismuth halides, thallium chloride, arsenic halides, phosphorus halides, sulphuric acid, nitric acid, sulphur, sulphur dioxide, sulphuryl chloride and organic acidsis. 

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