Sodium mercaptoacetate

Zhao Jing et al., 1988. Research on the mechanism of chalcopyrite depressed by sodium mercaptoacetic. Nonferrous Metals (part of mineral processing), (3) 42 - 45 Zhuo Chen and Yoon, R. H., 2000. Electrochemistry of copper activation of sphalerite. Inter. J. Miner. Process, 58 57 - 66... 

SYNS MERCAPTOACETIC ACID SODIUM SALT SODIUM MERCAPTOACETATE SODIUM... 

Sodium thiocyanide. See Sodium thiocyanate Sodium thioglycolate CAS 367-51-1 EINECS/ELINCS 206-696-4 Synonyms Acetic acid, mercapto-, monosodium salt Mercaptoacetic acid, sodium salt NaTG Sodium mercaptoacetate Sodium thioglycollate... 

In another series of experiments, a novel approach to the determination of nucleotide sequence was adopted by A. S. Jones, Stacey, and their co-workers. For example, when calf thymus DNA was treated with mercaptoacetic acid in the presence of zinc chloride and anhydrous sodium sulfate, it yielded aldehydo-apurinic acid bis(carboxymethyl) dithioacetal. When degraded with dilute alkali, this afforded dialyzable fragments, which were separated into at least 20 components. Some were identified, including mono-, di-, and tri-nucleotides, thereby revealing that DNA contain regions of at least three linked pyrimidine nucleotides. The same procedure was applied to the DNA isolated from M. phlei ... 

The thiomethyl group has also been employed as a leaving group. Treatment of 364a-f with the anion of ethyl mercaptoacetate followed by sodium ethoxide generates 365a-f (Equation 134) <2003J1C311>. 

Reaction of 3-benzenesulfonylpyrazine-2-carbonitrile with ethyl 2-mercaptoacetate and sodium carbonate gave 97% of ethyl 3-aminothieno[2,3- ]pyrazine-2-carboxylate <2006T11124>. 

Table I Effect ot Added Phenol and Sodium Benzoate on Oxidation of Ferrous Mercaptoacetate with Molecular Oxygen...

A direct and versatile synthesis of the thieno[2,3-6 ]pyrazine ring system was found by Schneller and coworkers and consists of the reaction of 2-chloro-3-cyanopyrazine (361) with ethyl a-mercaptoacetate in the presence of sodium carbonate (Scheme 106) (75JHC513, 76JHC273 cf. 79MI31703). The conversion of (362) to thieno[2,3- >]pyrazine (363) is accomplished by straightforward methods. The compound (363) forms colorless crystals with m.p. 44 °C. 

Bourguignon and coworkers in their preparation of thieno[2,3-6]pyrazine used methyl-pyrazine (364 Scheme 107) (80JHC257) as starting material. The chlorination of (364) yields 2-chloro-3-methyl- and 2-chloro-6-methyl-pyrazine in a ratio of 80 20. Without separation this mixture is treated with ethyl mercaptoacetate in the presence of sodium ethoxide to give (365) in 91% yield (based on 2-chloro-3-methylpyrazine). Oxidation of the methyl group to an aldehyde function and subsequent base catalyzed ring closure yields (366), which is transformed to (363) by the method depicted already in Scheme 106. 

Diethyl mercaptoacetal has been prepared by treating diethyl bromoacetal with potassium hydrosulfide 3 by the reduction of 1,1,11 -tetraethoxyethyl disulfide 3 with lithium aluminum hydride by reduction of 1,1-diethoxyethyl benzyl sulfide,3 41,1,1/,1/-tetraethoxyethyl disulfide,3 and 1,1,1, 1 -tetracthoxyethyl polysulfide 3 with sodium and liquid ammonia. The method described is adapted from the last-named preparation. Dimethyl mercaptoacetal has been prepared by the same methods.3... 

Dissolve 1.0 g of the nitrile and 2.0 g of mercaptoacetic acid in 25 ml of sodium-dried ether in a dry test tube or small flask. Cool the solution in ice and saturate it with dry hydrogen chloride (5-10 minutes). Stopper the test tube or flask and keep it at 0 °C until crystallisation is complete (15—60 minutes). Collect the crystals by suction filtration, wash with anhydrous ether and dry in a vacuum desiccator over potassium hydroxide pellets (to remove hydrogen chloride) and paraffin wax shavings (to remove ether). 

Dihydrogen TctrakisicarboxymethylthioIatoltellurateCII)1 Sodium tellurite and mercaptoacetic acid are combined in a 1 8 molar ratio in 1 normal sulfuric acid. The resultant mixture is extracted with ethyl acetate, the organic phase is shaken repeatedly with aqueous cadmium chloride solution to remove excess mercaptoacetic acid, the organic phase is dried with sodium sulfate, the mixture is filtered, and the solvent is evaporated at 0° under reduced pressure to leave yellow crystals of the product. 

Mix 25 ml of each of die diluted standard solutions and 25 ml of sodium chloride-potassium chloride solution with 25 ml of Trichloroacetic Acid-Mercaptoacetic Acid Reagent. Aspirate these solutions into the flame as for die sample. 

The practical utility of the facile addition of mercaptoacetic acid across the double bond of an azomethine has been used in the synthesis of thiazolo-triazolothiadiazin-6(7//)-one (328). Thus, 7//-3-methyl-5-triazolo[3,4-f>]thiadiazine hydrochloride (327), obtained by reacting l-amino-2-methyl-j-triazolyl-2-thione (326) with chloroacetaldehyde di-ethylacetal, reacts with mercaptoacetic acid in the presence of p-toluenesulfonic acid in boiling anhydrous benzene for 40 hr using a Dean-Stark water separator followed by basification with sodium bicarbonate to furnish 8a//,9//-3-methylthiazolo[3,2-u]-[l,3,4]triazolo(3,4-f>](1,3,4]-thiadiazin-6(7//)-one (328) (74IJC287) (Scheme 77). The absorption at 1725 cm (lactam carbonyl) in product 328 supports the cyclic structure in preference to the open-chain acid structure. 

The enzyme preparation from Aerobacier aerogenes was found by Hogness and Battley to be inactivated by oxygen, iodoacetamide, p-(chloromercuri)-benzoate, and A -ethylmaleimide. After inactivation with oxygen, activity could be recovered on treatment with mercaptoacetate, cysteine, sodium sulfide, sodium cyanide, or 2-mercaptoethanol." The authors, however, have not drawn any conclusion as to whether these observations should be taken to indicate that sulfhydryl groups are involved in the enzyme activity. 

Second generation products were mixed mono-/di-alkyl tin long-chain mercaptans. The stabilizer is synthesized directly from an appropriate combination of mono-n-butyltin trichloride and di-n-butyltin dichloride, which is reacted with a suitable quantity of /-octyl mercaptoacetate and sodium sulfide. Although the tin content in the stabilizer is increased to about 22%, these products are often used in diluted form to aid in their handling, while reducing losses. 

Nucleophilic substitution by salts of H2S will react with halogenated compounds to make mercaptides that can be acidified to mereaptans. The most convenient salts are sodium and ammonium hydrosulfides. Mercaptoacetic acid is made by the reaction of ammonium hydrosulfide with monochloroacetic acid followed by acidification. 

Purified mercaptoacetic acid is sold in anhydrous or 85% aqueous forms, most often for subsequent conversion to the esters or to the ammonium, sodium, potassium, or calcium salts. 3-Mercaptopropionic acid is produced from metal hydro sulfides and either acrylic acid or acrylonitrile. Mercaptoethyl tallate is another mercapto-ester used in commercial organotin stabilizers. It is manufactured by a standard esterification of mercaptoethanol and tall oil, a mixture of fatty acids. 

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