Thiosulfate, reaction with

The thiosulfate reaction with cyanide to give thiocyanate is the basis for the use of thiosulfate as an antidote in cyanide poisoning ... 

The thermodynamic aspect of the reaction mechanism is also worthy of detailed discussion. Table 5 shows thermodynamic quantities for the bromoacetate-thiosulfate reaction with and without added electrol3rtesi... 

These three methods are employed commercially. In addition, decomposition of polythionates in alkaline solution or their reaction with sulfide or sulfite gives thiosulfates ... 

Ana.lysls. The available chlorine (av CI2) in hypochlorite solutions or soHds is deterrnined by reaction with aqueous KI, followed by acidification with either acetic or sulfutic acid and titration of the Hberated iodine with standard thiosulfate. The av CI2 in a hypochlorite is a measure of the oxidi2ing capacity expressed in terms of elemental chlorine one hypochlorite ion is equivalent to one CI2 molecule. Thus pure Ca(OCl)2 has an av CI2 of 2 x mol wt... 

The reaction of a dibromochalcone with hydroxylamine hydrochloride in pyridine gave three products with the expected 2-isoxazoline product as the predominate compound. A ring bromination product and an isoxazole were also isolated (70UC796). The reaction of hydroxylamine with /S-thiosulfates of propiophenone at reflux produced 3-phenyl-2-isoxazo-line (455). At room temperature a bis-Michael product (456) was produced. The reaction with N -phenylhydroxylamine yielded a mono-Michael type product (457) (74CPB1990). 

C. Cyclobutanone (Note 16). The residue consisting of oxaspiro-pentane (35%) and dichloromethane (about 200 ml.) is added dropwise at room temperature to a magnetically stirred solution containing about 5-10 mg. of lithium iodide in 50 ml. of dichloromethane (Notes 17, 18), at such a rate as to maintain gentle reflux of the solvent. At the end of the addition when the reaction mixture returns to room temperature, the transformation into cyclobutanone is complete. The dichloromethane solution is washed with 20 ml. of saturated aqueous sodium thiosulfate and with 20 ml. of water. After drying over magnesium sulfate and concentration by distillation of the solvent through a 15-cm., helix-packed, vacuum-insulated column, the residual liquid consists of cyclobutanone (95%) and of 3-buten-2-one and 2-methylpropenal... 

Reaction of 2-pyrrolylbenzoic acid derivative 122 with PCI5 and subsequent reaction with diazomethane gave the diazoacetophenone 123 that upon treatment with silver oxide, sodium carbonate and sodium thiosulfate afforded acetic acid derivative 124, cyclization with acetic anhydride gave 125 (91JHC77) (Scheme 24). 

Tests. Chem analysis consists of reaction with KI soln and titration of the liberated I with Na thiosulfate soln. Instrumental analysis consists of measurement of the carbonyl absorption at 1760cm 1 using an infrared spectrophotometer. This procedure is valid for any physical state or soln strength of the acid (Ref 10)... 

Elemental sulfur dissolves in boiling aqueous sodium sulfite solutions with the formation of sodium thiosulfate (Na2S203). The reaction proceeds quantitatively if sulfur and excess sodium sulfite are boiled for some time in weakly alkaline solutions. In the cold, however, practically no reaction occurs. Alternatively, thiosulfate can be produced quantitatively in solution phase by using organic solvents to first dissolve sulfur and then accomplish the reaction with aqueous sulfite. In a parallel reaction, elemental selenium dissolves in alkaline sulfite solution to produce selenosulfate, SeSO ... 

Sulfur also reacts by undergoing addition reactions with several types of species. For example, thiosulfates are produced by the reaction of sulfur with sulfites. 

Periodate and iodate ions may both be removed by reaction with iodide ion in acid solution this yields free iodine which can be removed by extraction209 or by centrifugation210-—or the iodine can be converted to iodide ion by titration with sodium thiosulfate.211 Periodate and iodate ions are also readily removed from solution by use of an anion-exchange resin.211a... 

Although the reaction with thiosulfate and with iodide ions may be a mere reduction of the halide, the reaction with sodium benzoate would appear to be a radical dissociation induced by the attack of a negative ion. The fate of the benzoate ion is unknown. Tris-( -nitrophenyl)-methyl benzoate is a stable substance which does not dissociate into radicals.23... 

The value of k /ky, is larger than unity for reaction of thiosulfate ion with n-butyl bromide. There is insufficient evidence to know whether this difference is characteristic of micelle-assisted reactions of dianionic nucleophiles (Cuccovia et al., 1982a). 

The decomposition of thiosulfate ion is promoted in an acidic solution. If the white solid is Na2SOreaction with strong acids such as HC1. By contrast, if the white solid is Na2S203, S02(g) will be liberated and a pale yellow precipitate of S(s,rhombic) will form upon addition of HCl(aq). 

Reaction with Thiosulfate-Formation of Bunte Salt. 

The sulfur formed in this reaction mainly consists of Sg and Sg with small amounts of larger even-membered rings of which S12, a-Sjg cmd S20 could be isolated The iodine can be recycled by reaction with stoichiometric amoimts of sodium thiosulfate, and the sulfur mixture is separated by precipitation with pentane and recrystallization from CS2 yield of Sg 36 % Sg forms orange-yellow crystals... 

Sodium thiosulfate reacts with chlorine to form sodium bisulfate and hydrochloric acid. This reaction removes chlorine from aqueous solutions ... 

In order to obtain heterodimers a cysteine residue of one peptide has to be specifically activated for subsequent reaction with the cysteine residue of the second peptide. Thiols are activated by introducing an electron-withdrawing substituent that increases the responsiveness of the sulfur to nucleophilic substitution. This topic has been reviewed 41311 Of the various older methods known in sulfur chemistry for the preparation of unsymmetrical disulfides, i.e. thiosulfates,11321 S-alkylthiosulfonates,11331 5-alkylthiosulfinates,11341 sulfanyl-amines,11351 sulfanylimides,11361 sulfanyl thiocyanates and sulfenyl chlorides,1137,1381 sulfan-... 

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