Disulphones oxidation

If 30% hydrogen peroxide is used as the oxidant then stepwise oxidation occurs leading to the a-disulphone (equation 80)195. In this study the trioxide, RS02S0R, was not found but was assumed to be produced. 

The oxidation of disulphones with iodine in aqueous perchloric acid apparently produces the corresponding sulphonic acid (equation 95)212. 

Ten Brink et al. (2000) have shown how biphasic systems, sometimes with the sparingly soluble alcohols as one phase and an aqueous phase as the other phase, benefit from the strategy for air oxidation to aldehydes/ketones by using water soluble Pd complex of bathophenanthroline disulphonate. This is a nice example of green technology. 

Several xanthene derivatives are applied as acid dyes. For example, condensation of 3-diethylaminophenol with benzaldehyde-2,4-disulphonic acid, followed by cyclisation and oxidation, gives Acid Rhodamine B (6.197 Cl Acid Red 52). This dye is used in drop-on-demand ink-jet printing [36]. 

Glycerol can be oxidized to formaldehyde by periodic acid and the formaldehyde measured spectrophotometrically at 570 nm after reaction with chromotropic acid, or fluorimetrically after the addition of diacetylacetone and ammonia. The chromotropic acid reagent consists of 8-dihydroxynaphthalene-3,6-disulphonic acid dissolved in 50% sulphuric acid. 

Fifty grams of hydroxylamine disulphinate—prepared by the action of sulphur dioxide on a soln. of sodium nitrite—are dissolved in 35 c.c. of boiling water. The soln. is cooled by ice, and, while keeping the temp, below 30°, it is mixed with 10 c.c. of a concentrated solution of sodium hydroxide (1 1), and 90 c.c. more alkali-lye is then added. The mixture is heated to about 50° for 30-45 minutes, and poured into a litre of water. The undecomposed disulphonate and hydroxylamine are destroyed by adding yellow mercuric oxide, and the clear filtered soln. is made up to four litres and treated with silver nitrate so long as the light yellow silver hyponitrite is precipitated. The precipitate is washed with warm water until it is free from.acid. 

Santa Fe Springs, CA, USA Calfax Series Diphenyl oxide disulphonates... 

Mattocks has described a new method for oxidizing retronecine (27) to the unstable dihydropyrrolizine (28), using Fremy s salt (potassium nitroso-disulphonate).13... 

Oxidative dimerization of Fischer base (1,3,3-trimethylmethyleneindolenine) is reported77 to occur by means of potassium nitroso disulphonate (Scheme 54). 

Hough, L, Taha, M I, The disulphones derived by oxidation of 2-amino-2-deoxy-D-glucose diethyl dithioacetal hydrochloride and its A-acetyl derivative with peroxypropionic acid, J. Chem. Soc., 3564-3572, 1957. 

Some examples were found among photochemical reactions accompanying the electrode process, such as for anthrahydroquinone-2,6-disulphonic acid (Berg, 1963), where the anthraquinone formed by electro-oxidation is on illumination photochemically reduced back to the quinol. The quantitative treatment of this and similar types of photochemical reactions (Berg, 1964) is complicated by the fact that these reactions do not take place only at the surface of the electrode but in the bulk of the solution as well. 

Reduction of Cu(ll) to Cu(l) by the CuBD results in free radical formation and neurotoxicity in cell culture [118]. The APP CuBD peptide, as well as the full-length protein, induce lipid peroxidation in the presence of Cu(ll) and this is dependent on the APP CuBD-mediated Cu(l) formation [118, 122] (Table 1). That this toxic effect was not restricted to addition of exogenous, recombinant APP was shown by increased Cu toxicity in primary murine neurons when compared to APP-deficient neurons (APPo/o) [123]. Again, this toxic effect was Cu(l)-dependent as the Cu(l) selective chelator, bathocuproine disulphonate (BCS) could inhibit the increased Cu-mediated toxicity in wild-type neurons [122]. Whether APP-Cu directly or indirectly (through increased lipoprotein oxidation) contributes to AD pathology is uncertain, however, increased levels of APP (and Cu) are associated with senile plaques in AD brain. 

Another problem was to find a stable and cheap mediator and an effective regeneration system for the oxidized mediator. Table 14 shows the activity of different mediators. Under various aspects anthraquinone-2,6-disulphonate was especially useful. It is completely stable under the reaction conditions and can easily be reisolated if necessary. It works not only veiy well with HVOR but also with dimethyl-sulphoxide reductase present in Proteus mirabilis or P. vulgaris (Scheme 4). 

Space time yield based on 1 g F. vulgaris cells (dry weight). In 0.1 or 0.3 M Tris/HCl-buffer, pH 8.5. Due to the solubility of AQDS higher concentrations are not suitable. Carbamoylmethylviologen. Anthraquinone-2,6-disulphonate. Dimethyl-sulphoxide. iV-Methylmorpholine N-oxide. 

Oxidative decarboxylation of (2/ ,3S)-isocitrate from (2, 35 25,3/ )-isocitrate leading to (25,3/ )-isocitrate with NADP regeneration using isocitrate dehydrogenase (IC-DH, EC 1.1.1.42), AMAPORs in form of crude extracts of C. thermoaceticum, anthra-quinone-2,6-disulphonate and oxygen. The reaction mixture contained 140000 U catalase. 

For the enantioselective dehydrogenation of the ( -enantiomer from a racemic mixture of 3-hydroxybutyrate three different methods were used to regenerate NADP (Table 27) (83). The first method worked with catalytic concentrations of NADP and anthraquinone-2.6-disulphonate. NADPH was reoxidized by oxidized anthraquinone-2.6-disulphonate catalysed by AMAPOR (Reaction [31a]). The reduced anthraquinone-2.6-disulphonate was electrochemically reoxidized. In experiment 2 a method described by the Whitesides group (106) was applied for NADP regeneration. Oxidized anthra-quinone-2.6-disulphonate could also be used in stoichiometric concentrations (exp. 3). In such a case its electrochemical reoxidation was not necessary. Obviously in experiment 1 the product isolation is especially simple. 

The substance so formed yields on oxidation a disulphone, which is sulphonal —... 

The alkene-l,l-dithiolates (111), on phosgenation, give labile dithietanones (112), which give reactions typical of thioketens. The structure of the dimer of the lachrymatory factor (113) of onion has been re-assigned as (114), i.e. the first stable 1,2-dithietan derivative. Procedures for the oxidation of tetrafluoro- and tetrachloro-l,3-dithietans to the corresponding disulphones have been developed.Infrared and Raman spectral studies indicate that 1,3-dithietan is puckered (C21, symmetry) when free but planar (D2,-,) in the solid state. 

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