Dithioglycolic acid

Note Silica gel, kieselguhr and polyamide layers can be used as stationary phases. Not all acids are stained on RP layers. Amino layers yield a pale blue background. The detection limits are in the pg range for carboxylic acids [1], thioglycolic and dithioglycolic acids [2] and for antithyroid pharmaceuticals [4] they are about 5 ng per chromatogram zone for sterols and steryl esters [6]. 

In an elegant method for the isolation of translating ribosomes, the dihydrazide of dithioglycollic acid is first attached to cellulose, and treated with poly(rU) which has been oxidized at the 3 -terminus with periodate, to form (83). After passage of a... 

Experimental observations indicate that the oxidation of cobalt (II) to cobalt (III) and the formation of ethylenediamine from N-hydroxyethylethylene-diamine occur simultaneously. This is quite the opposite to what is usually assumed in other instances of transition metal catalysis of organic reactions—for example, the catalytic effect of manganese in the oxidation of oxalic acid (7, 8), of iron in the oxidation of cysteine to cystine (22) and of thioglycolic acid to dithioglycolic acid (5, 23), of copper in the oxidation of pyrocatechol to quinone and in the oxidation of ascorbic acid (29, 30), and of cobalt in the oxidation of aldehydes and unsaturated hydrocarbons (4). In all these reactions the oxidation of the organic molecule occurs by the abstraction of an electron by the oxidized form of the metal ion. 

Diphenyl-4,4 -dithioglycolic acid (73),321 diphenylmethane-4,4 -dithioglycolic acid (75a),322 diphenyl ether-4,4 -dithiogycolic acid... 

The reaction is approximately first-order with respect to each reactant (the second-order rate coefficient increases with increase of substrate concentration), and catalysis by hydroxide ions is observed. Henderson and Winkler studied the ferrous ion-catalysed oxidation of thioglycolicacidto dithioglycolic acid. The rate is sensitive to traces of metal ions, and reproducible results could not be obtained in the absence of the catalyst. The oxidation is first-order with respect to both peroxodisulphate and ferrous ions, and zero-order with respect to the substrate. The second-order rate coefficient is approximately equal to that determined in the absence of the substrate, so Henderson and Winkler suggested that the ratedetermining step is the oxidation of ferrous to ferric ions, as in reaction (96), and that this is followed by reaction (97) and then rapid oxidation of thioglycolic acid by ferric ions. 

Di-, tri- and polycarboxylic acids [1] Thioglycolic and dithioglycolic acids [2] Diuretics [3]--------------------------... 

The 2,2 -dithiobis(acetic acid), commonly named dithioglycolic acid, used by the checker was synthesized from HSCH,COOH and SOjCl, in diethyl ether. tThe checker obtained purple crystals at this stage. 

Thiogly colic Acid. Mercaptaacetic acid thioglycol lie acid. C,H402S mol wt 92.12. C 26.07%, H 4.38%, O 34.74%, S 34.81%. HSCHjCOOH. Prepd by the action of sodium sulfbydrate on sodium chloroacetate by electrolysis of dithioglycollic acid (from sodium sulfide and sodium chloroacetate). 

Disulphidoacetic Acid. Dithioglycollic acid, dithiodiglycollic acid, aym.-dicarboxydimethyl di-stUphidCt dimethyl diswphide dicarboxylic acid) HOOC-CH. S-8-CHo-COOH 04HeO Sa MW, 182... 

Thiourea- S Dithioglycollic acid- Sa Thiourea- S Thiourea- S DCl, DjO Thiourea- S... 

If iron III salts are present, it is well to use a 2 % solution of a,a -dip5nddyl in thioglycolic acid as reagent. The latter reduces ironm almost instantaneously with formation of dithioglycolic acid ... 

Dithiol is the trivial name of 4-methyl-l,2-dimercaptobenzene (I). Its solution in alcohol or dilute alkali reacts with weakly acid solutions of sulfide-forming metal ions to yield yellow to black precipitates. The magenta stannous salt (II or Ila) is formed from strong hydrochloric acid solutions of either Sn or salts. Sn v salts are reduced by the dimercaptan to give the aromatic disulfide. Since this disulfide is not soluble in water, it is better to use thioglycolic acid as reductant in all cases it is oxidized to water-soluble dithioglycolic acid. 

The extractability of labelled organotin compoimds (di-n-octyl [ C] tin-dithioglycollic acid-2-ethyl- -hexyl ester) from rigid polyvinylchloride (PVC), low and high-density... 

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