Reagents dithionite

Ellman s reagent" + dithionite Synthetic vesicles of dicetyldimethyl-ammonium bromide. Effects of vesicles and fast and slow reaction components separated Moss and Schreck, 1983... 

Note Phosphoric acid [8] and hydrochloric acid [6, 9] have both been suggested in the literature as substitutes for phthalic acid. The addition of sodium dithionite [9] is also occasionally mentioned and sometimes no additives are employed [10]. The alternative reagents offer no advantages over the phthalic acid containing reagent since they usually cause more background coloration. The limits of detection are about 0.1 —0.5 pg per chromatogram zone [5]. 

A small amount of sodium dithionite added to an aqueous medium depletes oxygen almost instantly. Due to the acidity of the reagent, a sufficiently strong buffer must be included in the medium. However, the use of dithionite is not recommended in the stages of extraction and purification because the reagent and its decomposition products are highly reactive and can cause undesirable reactions. 

This is by far the most important reaction of tetrazolium salts and accounts for the bulk of their many applications. A large variety of reagents can reduce tetrazolium salts, e.g., 53 to formazans, e.g., 51. Ascorbic acid, hydrazine, and hydroxylamine have been recommended for the preparation of formazans from tetrazolium salts.245 Stronger reducing agents such as ammonium sulfide, sodium amalgam, sodium dithionite, and catalytic hydrogenation can further reduce the formazans to the amidrazones, e.g.,... 

Rueda, E.H. Ballesteros, M.C. Grassi, R.L. Blesa, M.A. (1992) Dithionite as a dissolving reagent for goethite in the presence of EDTA and citrate. Application to soil analysis. Clays Clay Min. 40 575-585... 

Similar complexes can be prepared using other thiol-containing reagents and/ or by starting with hydroxylamine or with nitrite and a reductant such as sodium dithionite. Formation of the complex is favorable enough so that it can be quantitatively prepared. The reaction may be used as an assay for free iron (Salerno et al., (1976). 

An alternative furan-based jasmone synthesis has been accomplished through oxidative cleavage of this heterocyclic ring (73AJC2671). Thus, the furan (85) was oxidized with Collins reagent to the enedione (86) and the conjugated double bond reduced with sodium dithionite. Base cyclization then gave pure (Z)-jasmone (Scheme 21). 

A nitrochromone has three easily reducible functions and, for its reduction, conditions and reagents which have little or no effect on the carbonyl or the 2,3-double bond should be chosen. Nitrochromones are reduced by tin-hydrochloric acid, zinc-ammonium chloride, iron-acetic acid, iron-hydrochloric acid or sodium dithionite. It may be easier to control the severity of the conditions in catalytic hydrogenation. Scheme 29 shows that with proper choice of conditions (temperature, pressure, solvent, catalyst), it is often possible to optimize the yield of the desired product (527). Extending the reaction time from about 30 min to 2.5 h increased the yield of the chromanone (528) and none of the hydroxylamine (529) was then detected (70JCS(C)2230). 

Sodium borohydride, 277 Sodium dithionite, 277 Reagents which can be used to reduce cyclic ketones to equatorial (more stable) alcohols Potassium-f-Butanol, 277 Sodium-Propanol, 277 Sodium triacetoxyborohydride, 283 Reagents which can be used to reduce aldehydes selectively Dichlorotris(triphenylphosphine)-ruthenium(II), 107... 

Organocopper reagents, 207 Organovanadium reagents, 219 By desilylation of vinylsilanes Tetrabutylammonium fluoride, 286 By desulfurization of vinyl sulfides and related sulfur compounds Sodium dithionite, 281 Elimination reactions By dehalogenation Dichlorobis(cyclopentadienyl)-titanium, 102... 

Two different sets of conditions were utilized for carrying out the reduction of the nitro-substituted surface 4 for forming the aminated surface 5. One involved treatment with zinc and acetic acid at room temperature and the other consisted in reacting with aqueous sodium dithionite at room temperature. The former yielded an almost totally reduced amino surface 5, while the reduction was incomplete with the dithionite reagent. The amino surface 5 was characterized... 

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