Chloramine-B , oxidation

Chloramine B oxidizes HD to its sulfoxide via an intermediate containing an S-N bond (Whitman, 1995b). 

Aravamudan and Venkappayya75 oxidized dimethyl sulphoxide in acetate buffer of pH 4 to 4.5 and with a reaction time of only 1 min. They then added potassium iodide and acid and titrated with thiosulphate the iodine liberated by unused reagent. They reported that cerium(IV) and Cr(VI) were much less effective oxidizing reagents for the sulphoxide. A very similar procedure was used by Rangaswama and Mahadevappa76 to determine dimethyl sulphoxide and numerous other compounds with chloramine B. 

Chloramine-B (CAB, PhS02NClNa) and chloramine-T (CAT, p-Me-C6H4S02NClNa) have also been used for the oxidation of sulphoxides107-115. The required sulphone is produced after initial attack by the sulphoxide sulphur atom on the electrophilic chlorine-containing species, forming a chlorosulphonium intermediate as shown in equation (34). These reactions take place at room temperature, in water and aqueous polar solvents such as alcohols and dioxane, in both acidic and basic media. In alkaline solution the reaction is slow and the rate is considerably enhanced by the use of osmium tetroxide as a catalyst115. 

For the substitution of the angular methyl groups in steroids five methods are known (a) homolysis of N-chloramines [Loffier-Freytag reaction (only C-18)] (b) oxidation of alcohols with lead tetraacetate (c) photolysis of nitrite esters (d) homolysis of hypochlorites (e) the hypoiodite reaction. ... 

Catalysis of the oxidation of allyl and crotyl alcohols with chloramine-T, 375 chloramine-B, bromamine-T, and bromamine-B Catalysis of the chloramine-T oxidation of glycolic and lactic acids 376... 

T. A. Iyengar, P. Swamy, and D. S. Mahadevappa, Oxidation of some aldopentoses by chloramine-B in alkaline medium a kinetic and mechanistic study, Carbohydr. Res., 204 (1990) 197-204. 

Oxidation of piperidinone thiosemicarbazones with chloramine-T (CAT) is first order in CAT and fractional order in the substrate. The reaction showed an inverse fractional order dependence on acidity. A plausible mechanism has been indicated 98 Kinetics of oxidation of -propylamine and n-bulylaminc by CAT and chloramine-B (CAB) have been determined and mechanisms have been proposed.99 Mechanisms have been proposed and rate laws derived for the oxidation of dimethylglyoxime100 and p-crcsol101 with CAT. 

Labeling antibody with can be accomplished in several different ways (see the review by Skelley et alA) among the commonly used methods are (a) various modifications of Hunter and Greenwood s chloramine-T oxidation method, including that of Bolton and Hunter (b) the use of catalytic amounts of lactoperoxidase for iodination. ... 

JUWEID, M.E., Radioimmunotherapy of B-cell Non-Hodgkin s lymphoma From clinical trials to clinical practice, J. Nucl. Med. 43 (2002) 507-1529. ROBLES, A.M., BALTER, H., OLIVER, P., WELLING, M., PAUWELS, E.K.J., Improved radioiodination of biomolecules using exhaustive chloramine-T oxidation, Nucl. Med. Biol. 28 (2001) 999-1008. 

Iron is found to catalyze the reduction of peroxide-bound chromium(IV) by hydroxylamine in acetate buffered media. The proposed catalytic sequence involves recycling of dissolved iron between the 4-2 and 4-3 states, the rapid oxidation of Fe(II) by Cr(IV) (fc = 3 x 10 M" s" ), a rate-determining one-electron oxidation of Fe(III)-bound NH30H ion by Cr(IV), and the rapid reaction of Fe(III)(ONNH2) with excess NH30H. The kinetics of oxidation of HONH2-HC1 by chloramine-B in HCl medium have been reported. ... 

The rate of chloramine B (CAB) oxidation of ciprofloxacin in H2O-HCI is first order in CAB, substrate, and H" " ion and is affected by ionic strength, dielectric constant, and added reaction product formation of an intermediate complex by the conjugate acid (PhS02NHCl) and substrate in the slow step has been proposed. ... 

Method B Sample was oxidized with chloramine T, reacted with m-aminophenol and the absorbance was measured at 420 nm. 

---