Hydrogen bromide disulfide

Di-o-nitrophenyl disulfide was first prepared by the action of hydriodic acid on o-nitrobenzene sulfochloride.1 It has also been prepared by the reduction of o-nitrobenzene sulfinic acid with hydrogen bromide 2 by the reduction of ethyl-o-nitro-phenylsulfonacetate with ammonium sulfide 3 and by the deamination of 4,4,-diamino-2,2 -dinitrodiphenyldisulfide.4 The procedure given is the method of Blanksma5 as elaborated by Wohlfahrt.6... 

As methods of preparation, only the first three need be considered. It was decided not to try the direct action of bromine upon naphthalene, owing to the necessity of stirring the solid naphthalene and of collecting the hydrogen bromide gas the latter difficulty is also presented when carbon disulfide is used, and the objectionable properties of this solvent make its use further unfavorable. The third method, in which a suspension of naphthalene in alkaline hypobromite solution is treated with hydrochloric acid in aqueous solution, was found to give satisfactory results in so far as the yield of a-bromonaphthalene is concerned (though it was no better than with the method above described), but it presented considerable difficulties in the recovery of the hydrobromic acid. 

Ethyl alcohol Ethyl phthalate Hydrogen bromide Hydrogen chloride Hydrogen disulfide Isoamyl alcohol Isobutyl alcohol Nitrobenzene (crit.temp., upper layer, 40) o-Nitrobromobenzene (m.p. 42)... 

Concerning other transfer agents, silanes, phosphonates, disulfides or hydrogen bromide are able to react with such an olefin, yielding the monoadduct mainly (Table 18). 

Disulfides are obtained from sulfinic acids on reduction by hydrogen bromide in acetic acid solution 553,555-557... 

Copper(I) salt promoted reaction of styryl bromides with dibenzoyl disulfide in a hot aprotic polar solvent produces 2,4-diarylthiophenes (421) in moderate yields (Scheme 84) <92CL1947>. The reaction may involve addition of PhCOS radical to the double bond of the substrate (activated by copper(I) salt), further addition of the resulting radical (420) to the substrate, and intramolecular radical substitution with extrusion of benzoyl radical followed by elimination of hydrogen bromide. 

Dimethyl sulfoxide hydrogen bromide Sulfonic acids from disulfides with Og/KOH cf. 19, 126 with dimethyl sulfoxide in 0. G. Lowe, J. Org. Chem. 41, 2061 (1976) Me SO/HBr RSSR 2 RSO3H the presence of HBr s. 

Thiols react with dihydropyran in the presence of Bp3-Et20 (0°C, 0.5 h, 25 °C, 1 h) to yield (5)-2-tetrahydropyranyl hemithioacetals in satisfactory yields. In contrast to O-tetrahydropyranyl ethers, an 5-tetrahydropyranyl ether is stable to 4 N HCl-MeOH. Deprotection is conveniently accomplished with Silver(I) Nitrate (0°C, 10 min) or Hydrogen Bromide-Trifiuoroacetic Acid (90 min) in quantitative yields. Oxidation to disulfides can be carried out with lodine or Thiocyanogen ... 

The method described is adapted from the procedures of Kym 3 and Engelhardt, Latschinoff, and Malyscheff.4 Thio-benzoic acid has been prepared by the reaction of benzoyl chloride with potassium sulfide,4 hydrogen sulfide in pyridine,6 6 and magnesium bromide hydrosulfide.7 It is formed from dibenzoyl disulfide with potassium hydrosulfide,4 potassium hydroxide,4 8 and ammonia.9 It is also formed from dibenzoyl sulfide, from phenyl benzoate, and from benzoic anhydride with alcoholic potassium hydrosulfide.4 It has been obtained from dibenzoyl sulfide and hydrogen sulfide,10 carbon oxysulfide and phenyl-magnesium bromide,11 12 dibenzyl disulfide and sodium ethoxide,13 benzyl chloride and sulfur in the presence of potassium hydroxide,14 and benzylthiosulfuric acid and alkali.18 16... 

Methyldiiodoarsine [m.p. 30° b.p. 128° (16 mm.)] forms odorless yellow needles which melt to a red liquid and volatilize without decomposition at 200°. The compound is somewhat soluble in water and moderately soluble in alcohol, ether, and carbon disulfide the solubility is increased by the presence of hydrogen iodide. Hydrogen chloride or bromide converts the diiodoarsine into the corresponding chloro or bromo compound, while iodine oxidizes the compound to methylarsenic oxide.8 When boiled with dry sodium carbonate in the presence of benzene, methyldiiodoarsine forms the corresponding oxide.5... 

The alkylation of (21) with phenacyl or p-bromophenacyl bromide to yield the 1,3-dithiolylium salts (171) offers a more special case. The methylene group of these salts can be deprotonated to form the unstable thiocarbonyl ylides (172) which collapse to the non-isolatable episulfides (175). Further reaction of (175) by loss of sulfur produces (174) whereas episulfide ring-opening and hydrogen shift followed by air oxidation leads to the disulfide (173) (80BCJ2281). 

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