Thioglycolic acid methyl ester

Agemian and Bedak [42] have described a semi-automated method for the determination of total arsenic in soils. Chappell et al. [43] have described an inexpensive but effective method for the quantitative determination of arsenic species in contaminated soils. Chappell found that the extraction efficiency varied with the ratio of soil to acid and with the concentration of the acid. Rurikova and Beno [346] accomplished speciation of arsenic(III) and arsenic(V) in soils by cathodic stripping voltammetry. Wenclawiak and Krah [347] used reactive supercritical fluid extraction in speciation studies of inorganic and organic arsenic in soils. In this method, derivatisation with thioglycollic acid methyl ester was performed in supercritical carbon dioxide. Various other workers have discussed the determination of arsenic in soils [44-46]. 

K. Schoene, J. Steinhanses, H.-J. Bruckert and A. Konig, Speciation of arsenic-containing chemical warfare agents by gas chromatographic analysis after derivatization with thioglycolic acid methyl ester, J. Chromatogr., 605, 257-262 (1992). 

The chemical reactivity of [Rh l6)] was also examined in reactions with H-atom donors, where the complex behaves as a nucleophilic radical [90]. The reaction rates were dependent on the X-H bond dissociation energies, reacting rapidly with staimane (BusSn-H) and thiophenol, more slowly with ferf-butyl thiol and thioglycolic acid methyl ester and not at all with phenol and triphenylsilane [90]. 

CAS 2365-48-2 EINECS/ELINCS 219-121-7 Synonyms Acetic acid, mercapto-, methyl ester Mercaptoacetic acid methyl ester Methylmercaptoacetate Methyl-2-mercaptoacetate Thioglycolic acid, methyl ester... 

A simple gas chromatographic method determines total arsenic in urine as arsine with a PN detector. The detection limit is 50 ng. The gas sample is separated on a 1.2 m glass column filled with Chromosorb 103 80-100 mesh at a furnace temperature of 30 C [153]. MMAA and DMAA are separated as thioglycolic acid methyl esters on a glass column (1.8 m, 2 mm ID) packed with Chromosorb G AW-DMCS coated widi 2.5% XE-60 for flame ionization detection. The detection limit is 10 ng [154]. Triphenylarsine formation is a more time-consuming method. But the combination of a gas chromatograph with a microwave emission spectrometric detector reaches a detection limit of SO ng/Iiter. The method is also applied for the determination of alkylarsenic acids [132,155], Atomic absorption spectrometers [134] and mass spectrometers [135] were also used as detectors of gas chromatographs. 

Alternate Names methyl 2-mercaptoacetate, thioglycolic acid methyl ester, mercaptoacetic acid methyl ester, MTG. 

Mercaptoacetic acid 2-ethylhexyl ester. See 2-Ethylhexyl thioglycolate Mercaptoacetic acid methyl ester. See Methyl thioglycolate... 

To avoid the use of volatile, odiferous reagents like thioglycolic acid, an improved route (Scheme 4) employed benzhydryl thiuronium bromide 16 (which was isolated in 99% yield from the reaction of benzhydrol 12 and thiourea in HBr/water).29 Treatment of 16, as the HBr salt, with methyl chloroacetate 9 in the presence of K9CO3 and MeOH generated the methyl ester of benzhydrylsulfanyl-... 

Classification Nonaromatic ester Definition Ester of methyl alcohol and thioglycolic acid... 

During an exploration of practical syntheses of a GnRH antagonist, Farr et al. examined two key substrates for the Mitsunobu reaction.Both reactions were carried out at kilo-scale. Typically, four equivalents of the pyridyl ethanol 181 were required to drive the reaction to completion. Since the dinitrosulfonamide product 182 proved to be labile during the hydrolysis of the methyl ester, further exploratory work was carried out with the p-nitrosulfonamide 183. The nosyl group of the crude reaction product 184 was removed with thioglycolic acid. After an aqueous workup, the desired product 185 was obtained in 58% yield over three steps after recrystallisation from ethyl acetate. Eventually, this route was abandoned due to supply issues with the pyridyl ethanol and byproduct removal issues arising firom the Mitsunobu reaction and the nosyl deprotection. 

Figure 7.1 Extraction curve, migration of labelled Advastab TM-181 from PVC into HB 307 (1.5% additive in PVC film), TMSI methyl tin thioglycollic acid-2-ethyl- -hexyl ester. Reproduced with permission from J. Koch, Deutsche Lebensmittel-Rundschau, 1974, 70, 209. [1] 1974 Wissenschaftliche Verlagsgesellschaft mbH)...

TMSI Methyl tin thioglycollic acid-2-ethyl-n-hexyl ester... 

Pharmaceuticals and Agrochemicals. Thioglycohc acid and its esters are useful as a raw material to obtain biologically active molecules. In cephalosporine syntheses, (4-pyridyl)thioacetic acid [10351 -19-8] (65) and trifluoromethane (ethyl) thioglycolate [75-92-9] (66) are used as intermediates. Methyl-3-ainino-2-thiophene carboxylate can be used as intermediate for herbicidal sulfonylureas (67) and various thiophenic stmctures (68). 

Boron enolates of thioglycolates. Esters do not form boron enolates because of the low acidity of the a-protons. However, methyl phenylthioacetate (2) forms a boron enolate on treatment with Hunig s base and dibutylboryl triflate, and this enolate undergoes aldol reactions with aldehydes with high syn-diastereoselectiv-ity.1... 

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