Sodium thiosulfate, reaction with

Cyclophosphamide Cyclophosphamide or ifosfamide may be destroyed using alkaline hydrolysis in the presence of dimethylformamide or refluxing with hydrochloric acid, neutralizing, or reaction with sodium thiosulfate. The... 

Liquid phosgene is assayed by an iodometric method which iavolves the foUowiag reaction (52). The released iodine is titrated with sodium thiosulfate. 

Organic thiosulfate salts are usually prepared by the reaction of alkyl chlorides with sodium thiosulfate ... 

In this reaction, iodine is liberated from a solution of potassium iodide. This reaction can be used to assess the amount of ozone in either air or water. For determination in air or oxygen, a measured volume of gas is drawn through a wash bottle containing potassium iodide solution. Upon lowering the pH with acid, titration is effected with sodium thiosulfate, using a starch solution as an indicator. There is a similar procedure for determining ozone in water. 

The amount of sodium hypochlorite in a bleach solution can be determined by using a given volume of bleach to oxidize excess iodide ion to iodine CIO- is reduced to Cl-. The amount of iodine produced by the redox reaction is determined by titration with sodium thiosulfate, Na2S203 I2 is reduced to I-. The sodium thiosulfate is oxidized to sodium tetrathionate, Na2S406. In this analysis, potassium iodide was added in excess to 5.00 ml of bleach d = 1.00 g/cm3). If 25.00 mL of 0.0700 MNa2S203 was required to reduce all the iodine produced by the bleach back to iodide, what is the mass percent of NaCIO in the bleach ... 

For instance, in order to characterize the mixing performance of any transparent reactor, the reaction of discoloration of an iodine solution with sodium thiosulfate could be used according to the following reaction scheme ... 

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... 

Halides (X = Cl- and Br ) containing carbonyl groups react81 with sodium thiosulfate in aqueous ethanol until conversion to Bunte s salt. The crude reaction mixture diluted with a trapping diene and then added with triethyla-mine gives the a-oxothioketone adducts. 

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 number of moles of I3"(aq) produced is determined by titrating the iodide-treated sample with sodium thiosulfate. The balanced oxidation reaction that forms the basis for the titration is ... 

A sample of iodine-128 was produced in a Szilard-Chalmers reaction by irradiating a sample of ethyl iodide in a neutron source. The radio-iodine was extracted with sodium thiosulfate solution and then counted in a Geiger counter at various time Intervals. Use the tabulated data of t in minutes against C counts/min to find the rate equation and the half time. 

Principle. When serum is mixed with an Hb solution, the Hp is bound. The rate at which the mixture oxidizes I- to I2 in the presence of C2H5OOH is, under the conditions used, proportional to the HbBC (Hp content) of the serum. Hb added in excess is partially inactivated by addition of I2. The amount of I2 formed during the reaction is estimated by titration with sodium thiosulfate. 

Many high explosives can be synthesized from the reaction of picryl chloride with various nucleophiles. 2,2, 4,4, 6,6 -Hexanitrodiphenylsulfide (10) can be prepared from the reaction of picryl chloride (87) with sodium thiosulfate in ethanol solution in the presence of magnesium carbonate. Oxidation of (10) with fuming nitric acid forms 2,2, 4,4, 6,6 -hexanitrodiphenylsulfone (88). ... 

Dinitrochlorobenzene (95) reacts with pyridine to form 2,4-dinitrophenylpyridinium chloride (103), a reactive intermediate which readily reacts with a variety of nucleophiles. The reaction of (103) with hydrogen sulfide yields 2,2, 4,4 -tetranitrodiphenylsulfide (104), which on nitration-oxidation with fuming nitric acid, yields 2,2, 4,4, 6,6 -hexanitrodiphenylsulfoxide (105). The sulfide (104) is also formed from the reaction of two equivalents of 2,4-dinitrochlorobenzene (95) with sodium thiosulfate or sodium disulfide in aqueous ethanol. ... 

The workers who reported the chemistry described in Scheme 85, also reported a new preparation of this 8-thiapurine ring system via reaction of 6-amino-5-nitrosopyrimidine with sodium thiosulfate in acidic media (Scheme 86), and extended this methodology to the synthesis of 4-/3-D-ribofuranosyl[l,2,5]thiadiazolo[3,4-r/]pyrimi-dines <2007H(72)573>. The latter article includes the facile synthesis of these compounds, as well as the evaluation of antitumor and antiviral activity. 

This method can be used for the determination of the ozone concentration in the gas and/or liquid phase. The measurement takes place in the liquid phase, though, so that to measure a process gas containing ozone, the gas must first be bubbled through a flask containing potassium iodide KI. For the measurement of the liquid ozone concentration, a water sample is mixed with a KI solution. The iodide F is oxidized by ozone. The reaction product iodine 12 is titrated immediately with sodium thiosulfate Na2S203 to a pale yellow color. With a starch indicator the endpoint of titration can be intensified (deep blue). The ozone concentration can be calculated by the consumption of Na2S203. 

It is possible to perform an oxidation with Dess-Martin periodinane under almost neutral conditions by adding pyridine to the reaction flask in order to neutralize the acetic acid, which is generated during the oxidation, and performing the work-up by treatment with sodium thiosulfate in the presence of a sodium bicarbonate buffer.2... 

The reaction between sodium thiosulfate and hydrochloric acid can also be used to study the effect of temperature on the rate of a reaction. Figure 7.11 shows some sample results of experiments with sodium thiosulfate and hydrochloric acid (at fixed concentrations) carried out at different temperatures. You can see from the graph that the rate of the reaction is fastest at high temperatures. 

Chemical reactions Formation of trihalomethanes in treated water due to the presence of free chlorine Preservation with sodium thiosulfate to destroy excess chlorine cold storage... 

Activated alkyl halides react with sodium thiosulfate to form the Bunte salts 438 which, on treatment with base, generate thiocarbonyl compounds <1984CC922>. Trapping with 1,3-dienes affords 3,6-dihydro-2-//-thiopyrans in satisfactory yields and in a one-pot reaction, although with unsymmetrical dienes the regio and diastereo selectivities are not good (Scheme 143) <1996JOC4725>. 

Effluent-gas Analysis.4 This method of analysis gives an estimate both of the chlorine (IV) oxide produced and of the unreacted chlorine present in the effluent-gas mixture. The gas is collected in an opaque 600-ml. Hempel tube it is then absorbed in a neutral 10% solution of potassium iodide. Starch indicator is added to this solution or to an aliquot, which is then titrated with 0.1 AT sodium thiosulfate solution (titration A). The amount of sodium thiosulfate used is equivalent to all the chlorine gas in the sample plus one-fifth of the chlorine(IV) oxide. The solution is then acidified with an excess of 30% acetic acid, causing a second release of iodine, which is then titrated with sodium thiosulfate solution (titration B). The amount of sodium thiosulfate used in titration B is equivalent to four-fifths of the chlorine (IV) oxide in the sample. The equations for the reactions involved are shown below.4... 

Diethyl thioxomalonate, S=C(COOC2H5)2 (1). This reagent can be generated in situ from the Bunte salt (2) prepared by reaction of diethyl chloromalonate with sodium thiosulfate. 

It was found impossible to measure the rate of decomposition by the evolution of gases because the release of these gas bubbles is very slow and erratic. The course of the reaction was followed by analyzing samples for the ammonium ion. Small amounts of the decomposing amalgam were forced through a capillary tube into a chilled solution of an iodate. The ammonium reacted with iodate ion to give iodide ion. The solution was then acidified with acetic acid and the iodine distilled out, collected and titrated with sodium thiosulfate. The method was checked with samples... 

The bromination of cinnamic acid dissolved in carbon tetrachloride or other inert solvent.offers a convenient system for study. The dibromocinnamic acid produced remains in the carbon tetrachloride solution. The thermal reaction is so slow that it can barely be measured at room temperature and it is entirely negligible in comparison with the photochemical reaction at ordinary intensities. The quantum yield is so large that considerable reaction occurs even if the intensity of light is much reduced by the monochromator or other device for confining the light to a narrow range of frequencies. Furthermore, the reaction is easily and accurately followed by titration with sodium thiosulfate. Potassium iodide is added and the iodine liberated is a measure of the remaining bromine. 

Representative procedure. To a solution of Sml2 in THF (2.2 mmol) at —78 °C was added a mixture of the aldehyde (1.0 mmol) and acylated oxazolidinone (1.0 mmol) in THF dropwise over 5 min. The resulting solution was then stirred at —78°C for 30 min, during which time the reaction mixture decolourised. The solution was then quenched with 0.1 M HC1 and the aqueous layer extracted with Et20. The organic layers were washed with sodium thiosulfate and brine, dried (MgS04) and concentrated in vacuo. The crude product was purified by preparative TLC (ethyl acetate-hexane as eluent). 

This reaction may be used to estimate Cu2+ in solution for, it may be remembered, free iodine (or, more conveniently) the tri-iodide ion, I7, may be easily titrated with sodium thiosulfate. Cuprous oxide, Cu20... 

Assays of bromate and perbromate concentrations are required during the procedure. Bromate concentrations that are at least comparable to the perbromate may be determined iodometrically by reaction with sodium iodide in acid solution containing molybdate, followed by titration with standardized thiosulfate. After reduction of the bromate the solution should be ca. 0.1 M each in H+ and in free iodide ion. Perchloric, hydrochloric, or sulfuric acids may be used. The molybdenum(VI) concentration should be ca. 10 3 M. 

Although many workers have reported studies with 1,3-dithiane,3 7 no satisfactory description of its preparation has been published. Generally, 1,3-propanedithiol and formalde-hyde3,5,7 have been used as components in one instance, 1,3-dibromopropane was treated with sodium thiosulfate to form a precursor of the dithiol which was used as such with formalin.4 The formation of linear condensation products is a serious side reaction under such conditions. 

CUCI2 has been studied spectroscopically at 1000 °C in the presence of CI2 (to prevent decomposition to CuCl and Cb). Binary copper compounds with very soft iodide ligands are not known by simply adding 1 to a solution of Cu +, Cul and I2 are quickly formed. This reaction can be used for the volumetric analysis of Cu + in solution by titrating the I2 produced with sodium thiosulfate (equation 8). Hydrates of the dihalides (F, Cl, Br) are common, easily prepared from aqueous haloacids, and contain coordinated water molecules. 

AUcoxycarbonylsulfenyl chlorides react at 20 ° with aqueous potassium iodide primarily with halogen exchange. The sulfenyl iodides, R8I, are unstable and combine in a bimolecular reaction to give the disulfane and elemental iodine (equation 19), which is removed by washing the organic phase with sodium thiosulfate (equation 20). " " ... 

To a solution of 0.141 g (0.9 mmol) of /V,/V-2-trimethyl-4-pcntcnamidc (3) in 5 mL of DME/H20 (1 1) are added 1.1-2 equiv of iodine at 20 °C. The homogeneous reaction mixture is stirred for 4 d, then diluted with Et20, treated with sodium thiosulfate and extracted with two 10-mL portions of bt20. The extracts are washed with sat. NaHCO, and brine. After drying over MgS04 the ethereal solution is concentrated yield 0.183 g (85%) d.r. (trans/cis) 90 10 (determined by H NMR) bp IOO C/O.3 Torr. 

Thio-D-xylopyranose has been the sugar of this type most thoroughly investigated. Its synthesis was reported in 1961, independently and simultaneously from three different laboratories. With sodium thiocyanate, l,2-0-isopropylidene-5-0-p-tolylsulfonyl-a-D-xylofuranose (211) gives a thiocyanate that reacts with sodium sulfide to give l,2-0-isopropylidene-5-thio-a-D-xylofuranose (212). A better synthesis is the treatment of 211 with sodium thiosulfate, followed by reduction of the resultant Bunte salt with sodium boro-hydride. The same compound 212 is obtained by nucleophilic replacement of the 5-sulfonyloxy group in 211 by treatment with potassium thioacetate followed by deacetylation to 212, or by the reaction of 211 with sodium a-toluenethioxide, followed by scission of the resultant S-benzyl compound with sodium in liquid ammonia. 

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