Diphenyl sulfite

Aromatic polysulfites can be produced if bisphenols, eg, bisphenol A, are heated with diphenyl sulfite in the presence of lithium hydride (112). Halosulfates and Halosulfites. A general method for the preparation of alkyl halosulfates and halosulfites is the treatment of the alcohol with sulfuryl or thionyl chloride at low temperatures while passing an inert gas through the mixture to remove hydrogen chloride (113). 

The alcoholysis of sulfites such as dimethyl sulfite offers a convenient method for the preparation of high-boiling dialkyl sulfites [33]. Earlier, Voos and Blanke [8a] reported that dimethyl sulfite is converted to diethyl sulfite in 44 % yield. The reaction was shown to be acid-catalyzed and failed when barium carbonate was present. However, a patent refers to the use of lithium hydride in the transalcoholysis of 2,2-(4,4 -dihydroxyphenyl)propane with diphenyl sulfite or di-o-cresyl sulfite [32]. Recently Mehrotra and Mathur [34] reported that the alcoholysis reaction proceeds in the absence of catalysts. Their results are summarized in Eqs. (21)—(23) and Table VII. Tertiary butanol did not... 

Diphenyl sulfite decomposes PET immediately after its addition and lowered the degree of polymerization. Diphenylbenzene phosphite increased the degree of polymerization but 57% (calculated as P) of the added phosphite remained in PET, resulting in a lower softening point. Dicyclohexyl terephthalate lowered the degree of polymerization. 

Thionylaniline Diphenyl sulfite (30) Dialkyl sulfate, (CHsOkSO, Dimethyl pyrosulfate Sulfoxonium salts Disulfides, n-Butyl disulfide, Amyl-,... 

Kinetics for the cleavage of the third peptide (Table I) were similar to those for the one preceding. Cleavage of the remaining peptides was slow, ranging from 5-50% after 18 hours of incubation (15-150 nmole/min/mg enzyme). Phenyl sulfite (also termed diphenyl sulfite) was cleaved by pepsin and cathepsin D at closely comparable rates about 12 nmole/min/mg enzyme at a substrate concentration of 50 yM. Phenyl sulfite is hydrolyzed by a number of acid proteases (11), but its cleavage by cathepsin D has not been previously reported. 

RuCyaq. Na(lO )/CH3CN-CCiy0°C (D-mannitol-1,2 5,6-diacetonide-2,3-cyclic sulfite (6 g) to the sulfate) [116], and stoich. RuOyCCl (ca. 5 g methyl-p-tolyl, meth-ylbenzyl and triphenyl-methyl phenyl and diphenyl sulfides to the sulfones) [99,122],... 

Alkali metal hydrogen sulfites reduced dibenzo-1,4-oxatellurin 10,10-diacelate to dibenzo-1,4-oxatellurin and diphenyl tellurium diacetate to diphenyl tellurium5. Other reducing... 

Diphenyl Naphthyl Telluronium Iodide1 10 g (28 mmol) of diphenyl tellurium dichloridc are dissolved in 250 ml of dry toluene. A solution of 1 -naphthyl magnesium bromide in diethyl ether is prepared from 17.4 g (84 mmol) of 1-bromonaphthalene. The solution of the tellurium compound is quickly poured into the freshly prepared Grignard solution, the mixture is shaken vigorously, and 20 ml of dilute hydrochloric acid are added immediately. The solution is decanted from the precipitate, the precipitate is dissolved in boiling water, silver chloride is added, and the mixture is heated. The mixture is then filtered, sodium sulfite is added to the filtrate, and the telluronium iodide is precipitated by the addition of potassium iodide yield 11.8 g (78%) m.p. 148° (from ethanol, ethanol/diethyl ether). 

Diphenyl disulfide. In a 100-mL, round-bottomed flask equipped with a magnetic stirrer are placed 11.0 g (10.25 ml, 0.1 mol) of benzenethiol and 50 mL of trifluoroethanol (Note 1). The mixture is stirred and cooled in an ice bath (Note 2) and 12.5 mL (3.73 g, 0.11 mol) of 30% aqueous hydrogen peroxide (Note 3) is added dropwise over a period of 15 min through an addition funnel. After completion of the addition, the ice bath is removed and the reaction mixture is allowed to stir at room temperature for 24 hr. Diphenyl disulfide is sparingly soluble in trifluoroethanol and precipitates out of solution. The solids are collected on a Buchner funnel and dried under vacuum to afford 10.6 g of diphenyl disulfide (97%) (Note 4). Sodium sulfite 2.52 g (0.02 mol) is added to the mother liquor to decompose the excess peroxide and the mixture is heated in a water bath at 50°C for 30 min. A starch iodide test is negative. The liquid is transferred to a 100-mL, round-bottomed flask, fitted with a distillation unit having a Vigreux column (5 cm). The flask is heated in an oil bath and the solvent is distilled to recover the trifluoroethanol (Note 5). 

Dioxo-l,3-diphenyl-4ff,10/7-[l]benzothieno[5,6-6][2]benzotellurophene Several g of powdered tellurium are dissolved in aqua regia, the solution is heated until all nitrogen oxides have been expelled, and is then diluted with water. A solution of sodium hydrogen sulfite is added to precipitate amorphous tellurium. The tellurium is filtered off, washed with water until the washings arc neutral, and then several times with ethanol. 50 ml of xylene are placed in a nitrogen-flushed, 250 ml flask fitted with a reflux condenser. 638 mg (5 mmol) of the moist, amorphous tellurium and 502 mg (0.5 mmol) of the rhodium metallocycle are added. The mixture is refluxed under nitrogen for 8 h while a spatula tip of tellurium is added every 2 h. The mixture is then filtered, and the filter is placed on a silica gel column which is eluted with 9/1 benzene/petroleum ether. The second yellow band is collected, the solvent is evaporated, and the residue is crystallized from benzene/ethanol yield 100 mg (38%) m.p. 248°. 

The first synthesis of dibenzotellurophene was accomplished by Courtot and Bastani90 by treating diphenyl (39) with tellurium tetra-bromide or tetrachloride and then reducing the adduct (40) with potassium hydrogen sulfite [Eq. (8)]. 

Interestingly, thermal decomposition of 4,5-diphenyl-l,3,2-dioxathiolane 2-oxide depends on the stereochemistry of the starting diols. For example, the cyclic sulfite derived from meso-hydrobenzoin (66a) decomposed on heating to give a good yield of desoxybenzoin (67), while the trans isomer 66b (derived from if/-hydrobenzoin) furnished diphenylacetaldehyde (68) quantitatively [Eqs. (16) and (17)]. 

Cyclic sulfites derived from catechol or substituted catechol and ethene-1,2-diol 69 undergo elimination of sulfur monoxide to furnish diketone 70. For example, 4,5-diphenyl-l,3,2-dioxathiole 2-oxide or 2,2-dioxide furnished benzil [53LA(584)199 63JOC1075 86JOC1100] [Eq. (18)]. 

One of the earliest nucleophilic reactions of ethylene cyclic sulfite was reported with phenylmagnesium bromide (56JA454). Depending on the reaction conditions, a 3.4 to 23% yield of bromohydrin and a 42-60% yield of diphenyl sulfoxide were isolated [56CI(L)490j. 

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