Sulfonic acids from sulfoxides

The end product of the oxidation of mercaptans, sulfides, disulfides, sulfoxides, sulfones, etc., is a sulfonic acid. From a preparative stand-... 

Dimethyl sulfoxide/hydrogen bromide Sulfonic acids from mercaptans s. 31,82... 

Dimethyl sulfoxide hydrogen bromide Sulfonic acids from disulfides with Og/KOH cf. 19, 126 with dimethyl sulfoxide in 0. G. Lowe, J. Org. Chem. 41, 2061 (1976) Me SO/HBr RSSR 2 RSO3H the presence of HBr s. 

In addition to the stereospecific sulfoxide syntheses mentioned above, optically active sulfoxides of high optical purity may be prepared from optically active sulfoximides 60, which are sufficiently basic to form salts with optically active sulfonic acids and can be easily resolved into enantiomers. The stereospecific conversion of sulfoximides 60 into the corresponding sulfoxides was effected by... 

The second synthesis of the enantiomer of this sulfone entails two transformations. First, (-)-a-naphthyl p-tolyl [ 0] sulfoxide 141 was converted into the corresponding [ 0] sulfoxide 141 by the method of Johnson (with inversion of configuration). Its oxidation with m-chloroperbenzoic acid afforded the chiral sulfone (+)-142 (Scheme 8). The latter procedure was also used for the preparation of chiral (-)-[ H2lbenzyl p-tolyl [ 0 0]sulfone (143) from (-)-[ H2] benzyl p-tolyl sulfoxide 37. 

Rajagopal et al. (1984) used numerous compounds to develop a proposed pathway of degradation of aldicarb in soil. These compounds included aldicarb oxime, A-hydroxymethyl aldicarb, A-hydroxymethyl aldicarb sulfoxide, A-demethyl aldicarb sulfoxide, A-demethyl aldicarb sulfone, aldicarb sulfoxide, aldicarb sulfone, A-hydroxymethyl aldicarb sulfone, aldicarb oxime sulfone, aldicarb sulfone aldehyde, aldicarb sulfone alcohol, aldicarb nitrile sulfone, aldicarb sulfone amide, aldicarb sulfone acid, aldicarb oxime sulfoxide, aldicarb sulfoxide aldehyde, aldicarb sulfoxide alcohol, aldicarb nitrile sulfoxide, aldicarb sulfoxide amide, aldicarb sulfoxide acid, elemental sulfur, carbon dioxide, and water. Mineralization was more rapid in aerobic surface soils than in either aerobic or anaerobic subsurface soils. In surface soils (30 cm depth) under aerobic conditions, half-lives ranged from 20 to 361 d. In subsurface soils (20 and 183 cm depths), half-lives under aerobic and anaerobic conditions were 131-233 and 223-1,130 d, respectively (Ou et al, 1985). The reported half-lives in soil ranged from approximately 70 d (Jury et ah, 1987) to several months (Jones et al, 1986). Bromilow et al. (1980) reported the half-life for aldicarb in soil to be 9.9 d at 15 °C and pH 6.34-7.0. 

Polymerization and Spinning Solvent. Dimethyl sulfoxide is used as a solvent for the polymerization of acrylonitrile and other vinyl monomers, eg, methyl methacrylate and styrene (82,83). The low incidence of transfer from the growing chain to DMSO leads to high molecular weights. Copolymerization reactions of acrylonitrile with other vinyl monomers are also tun in DMSO. Monomer mixtures of acrylonitrile, styrene, vinylidene chloride, medially sulfonic acid, styrenesulfonic acid, etc, are polymerized in DMSO—water (84). In some cases, the fibers are spun from the reaction solutions into DMSO—water baths. 

Oxidation of 6-oxopyrido[2,l-h][l,3]thiazine-4,9-dicarboxylates (85 n = 0, R = H, phthalamido) with 1 mol eq of 3-chloroperoxybenzoic acid yielded sulfoxides (85 n = 1, R = H, phthalamido) [83JCS(CC)199 92JCS(P1)621]. Oxidation of 2,3,4,6,7,llh-hexahydro[l,3]thiazino[2,3-a]-isoquinolin-4-ones with 3-chloroperoxybenzoic acid in dichloromethane gave sulfones (69FRP1552211). The appropriate sulfone was also prepared from perhydropyrido[2,l-h][l,3]thiazine (59AP165) and 3,4,7,8, 9,10-hexahydro-2//,6//-[ 1,3]thiazino[3,2-h] isoquinolin-6-one [79JAP(K)79/ 92996 81USP4284778]. 

Pfaendler s study deals with the preparation of both penem sulfoxides 43 and sulfones 45 from 42 using the required amounts of OT-chloroperbenzoic acid (MCPBA) as depicted in Scheme 25. In a second step, 43 and 45 were converted into their respective potassium salts 44 and 46. However, catalytic hydrogenation on 45a resulted in product decomposition, as 46a was too labile to be isolated <1997BML2217>. 

Cysteic acid is obtained in nearly quantitative yield from cysteine with aqueous hydrogen peroxide in the presence of iron(II) ions.397 Molybdates and tungstates have also been used as effective catalysts for similar transformations.398 An excellent route for the oxidation of 2-thioethanol to isothionic acid has been developed.399 Heteropolyoxometallates supported on alumina400 can also be used to oxidize a range of organo-sulfur compounds. For example, alkyl monosulfides to sulfoxides and sulfones, and thiols to sulfonic acids are a few possibilities (Figure 3.98). 

Tetramethylsilane became the established internal reference compound for H NMR because it has a strong, sharp resonance line from its 12 protons, with a chemical shift at low resonance frequency relative to almost all other H resonances. Thus, addition of TMS usually does not interfere with other resonances. Moreover, TMS is quite volatile, hence may easily be removed if recovery of the sample is required. TMS is soluble in most organic solvents but has very low solubility in water and is not generally used as an internal reference in aqueous solutions. Other substances with references close to that of TMS have been employed, and the methyl proton resonance of 2,2-dimethylsilapentane-5-sulfonic acid (DSS) at low concentration has emerged as the reference recommended by IUPAC for aqueous solutions.55 Careful measurements of the DSS-TMS chemical shift difference when both materials are dissolved at low concentration in the same solvent have shown that for DSS 5 = + 0.0173 ppm in water, and 8 = — 0.0246 ppm in dimethyl sulfoxide. Thus, for most purposes, values of 8 measured with respect to TMS or DSS can be used interchangeably. 

Many other peroxy acids, such as trifluoroperacetic acid (equation 26), peroxydodecanoic acid (equation 27) and various perbenzoic acids " are also useful oxidants to give a high yield of sulfones from sulfoxides or directly from sulfides under suitable conditions. 

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