Dimethyl sulfide, conversion compounds

Bromobis[2,3-butanedione dioximato( 1 -)] (4-terf-butylpyridine)cobalt(lIl) is a tan, microcrystalline solid with greatly enhanced solubility in organic solvents compared to the chloro(pyridine) analogue. It is also the compound of choice in preparing alkylcobaloximes by the subsequent procedure because of the ease of isolation of the resultant products. In addition, the bromo(4-ferf-bupy) species react directly with electron-rich olefins, such as ethyl vinyl ether, in the presence of ethanol to yield, in this case, bis[2,3-butanedione dioximato(l-)]-(2,2-diethoxyethyl)(pyridine)cobalt(III).1J Conversion of the dimethyl sulfide compound to the pyridine derivatives is readily detected by a characteristic infrared absorption at 1600 cm 1 (pyridine stretch). The H nmr spectrum of bromobis[2,3-butanedione dioximato(1 -)] (4-ferf-butylpyridine)cobalt (III) has absorptions in the alkane region in the ratio of 3 4 at 6 1.25 ppm [Py—C (CH3)3 ] and 6 2.43 ppm (dh—CH3) from tetramethylsilane. 

Enantioselective aldol reactions. Enders et ul. have reported a regiospecific and enantioselective aldol synthesis. The method involves conversion of a methyl ketone into the chiral hydrazone 2, a-metalation, reaction with a carbonyl compound, and silylation to form a doubly protected ketol 3. The chiral ketols 4 are obtained by oxidative hydrolysis with H2O2 (30%) at pH 7 or by sensitized photooxidation in THF followed by reduction with dimethyl sulfide. Optical yields are 30-60%. The absolute configuration of the ketols is not known at present. 

Dimethyl sulfide is the most abundant of all the biogenic organo-sulfiir compounds, and the available data show that the H atom abstraction reaction with NO3 could contribute significantly to the conversion of NO to HNO3 in polluted coastal regions (Hjorth, Le Bras/Poulet). 

Dithioacetals, 1,3-dithianes or 13-dithiolanes are prepared by reaction of the corresponding carbonyl compound in the presence of an acid catalyst (cone. HQ, Lewis acids such as Znh, BFs EtaO, TMS-Cl, etc.) with a thiol or dithiol. Silica gel treated with thionyl chloride was found to be an effective as well as selective catalyst for thioacetalization of aldehydes. Thioacetalization can also be achieved using a (polystyryl)diphenylphosphine-4odine complex as a catalyst Conversion of aldehydes or acetals into 1,3-dithianes is achieved with the aid of organotin thioalkoxides and organotin triflates or with 2,2-di-methyl-2-sila-l,3-dithiane. Direct conversion of carboxylic acids to 1,3-dithianes can be carried out by reaction with 1,3,2-dithiabomenane-dimethyl sulfide and tin(II) chloride or 1,3,2-dithiaborolene with trichloromethyllithium followed by basic hydrolysis. 

Oxidations. WChlorosuccinimide-dimethyl sulfide (NCS-DMS) is one of several reagents for converting alcohols to alkoxydtmethylsulfonium salts, which in the presence of base convert to the corresponding carbonyl compounds via intramolecular proton transfer and loss of dimethyl sulfoxide. These oxidations are among the mildest and most selective for conversions of alcohols to aldehydes and ketones. This reaction does not suffer the overoxidation to acids or the carbon-carbon bond cleavages which are often encountered in chromium(VI) or manganese(VII) oxidations (eq 1). ... 

Fig. 6.4 Schematic illustration of the key pathways in the atmospheric cycle of S involving (7) the natural emissions of reduced S compounds such as H2S frran terrestrial biota and dimethyl sulfide (CH3SCH3) from oceanic biota (2) anthropogenic emissions of S compounds, principally SO2 (3) the oxidation of reduced S compounds by OH and other photochemical oxidants leading to the production of intermediate oxidation state S compotmds such as SO2 and methane sulfonic acid (MSA) (4) the oxidation of these mtermediate oxidation state compounds within the gas phase by OH-producing H2SO4 vapor (5) the conversion of intermediate oxidation state compounds within liquid could droplets, which upon evaporation yield sulfate-containing particles (6) the conversion of H2SO4 to sulfate-containing particles and (7) the ultimate removal of S fiom the atmosphere by wet and dry deposition (Chameides and Perdue 1997)...

Chemical derivatization can also be used for structure elucidation in complex mixtures. For instance, dimethyl sulfide has been used to differentiate peracids from other peroxy compounds. The rate of conversion of dimethyl sulfide into dimethyl sulfoxide is almost instantaneous with peracids [Eq. (25)], whereas it is slow with sec- and tert-hydroperoxides [Eq. (26)]. 

Araki et al. have found that La wesson s reagent, 2,4-bis(4-methoxyphenyl)-l,3-dithiaphos-phetane-2,4-disulflde, provides a convenient one-step conversion of mesoionic olates to mesoionic thiolates <88BCJ2977>. Thus 3-phenyl-1,2,3,4-thiatriazolium-5-olate (170) was converted to (171) in high yield by refluxing for 50 min in benzene (Equation (14)). This eompound had previously been prepared from compound (161 R = Ph) by treatment with sodium sulfide in aqueous dimethyl-formamide at room temperature <79JCS(Pi)732>. 

The triazolo[l,5-a]pyridine-2-sulfonanilides (30) can be prepared by the general route as outlined in Scheme 2.4.5 [49, 50]. The intermediate 2-benzylthio-triazolo[l,5-a]pyridine (31) is prepared starting from an appropriately substituted 2-aminopyridine. The 2-aminopyridine is reacted with 0-mesitylenesulfonylhy-droxylamine to give the N-aminopyridinium mesitylate (32). Compound 32 is then reacted with thiocarbonyldiimidazole followed by benzyl chloride to give 31. Conversion of the benzyl sulfide, 31, into the corresponding sulfonyl chlorides (33) is accomplished with chlorine and water. The sulfonyl chlorides are converted into the desired sulfonanilide (30) by reaction with aniline in the presence of pyridine and a catalytic amount of dimethyl sulfoxide. 

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