Dimethyl sulfoxide tolerant

It is evident that some leeway is available in the substituents tolerable in the m-position. The bronchodilator sulfonterol (28) is descended from this observation. Chloromethylanisole (29) is reacted with methylmereaptan to give 30, and the newly introduced group is oxidized to the methyl-sulfonyl moiety of 31 with hydrogen peroxide. Ether cleavage, acetylation and Fries rearrangement of the phenolic acetate produces 32, which is next brominated with pyrrolidinone hydrobromide tribromide and then oxidized to the glyoxal (33) with dimethyl sulfoxide. 

Concentration Plus Solvent Transfer. Concentration of the organic solutes is essential to the determination of many organic contaminants present in water at very trace levels. The solvent transfer is needed for implementation of the separation and detection schemes that do not tolerate the water matrix. For bioassay work, concentration and solvent transfer are also needed because the amounts are too low for direct testing of the water solutions, and dimethyl sulfoxide. (DMSO) is the preferred solvent. In bioassay studies that involve animal exposure, the concentration scheme must accommodate very large volumes of water. Theoretically and practically, these elements of the analytical and bioassay methodologies can be achieved by using solid adsorbents, especially synthetic polymers. 

Another technique is to transfer the separated protein from an SDS-PAGE gel to nitrocellulose. The protein-bearing nitrocellulose can be solubilized with dimethyl sulfoxide (DMSO), mixed with Freund s adjuvant, and injected into a rabbit. However, although rabbits readily tolerate DMSO, mice do not, thus making this method unsuitable for raising monoclonal antibodies. 

Solvent extraction is suitable for treating virtnaDy all varieties of feedstock, indudii the richest in benzene, although it appears illogical to dissolve most of this aromatic cut to release only a small part T e presence of a significaot amount of olefins (about 1 per cent) can be tolerated by certain solvents, such as K-methylpyTToUdone and dimethyl sulfoxide. 

The range of substrates which have been oxidized by activated dimethyl sulfoxide covers a wide range of tolerant functional groups, and there are many reports of how these oxidations proved superior to others that were investigated. 

A very mild oxidation procedure that tolerates a variety of other functional groups is the oxidation of alcohols to aldehydes and ketones by the dimethyl sulfoxide (DMSO). A DMSO solution of the alcohol is treated with one of the several electrophilic dehydrating reagents. The alcohol is oxidized to the aldehyde or ketone and DMSO is reduced to dimethyl sulfide (DMS), which is a volatile liquid (b.p. 37°C). Since pure DMSO freezes at 18°C and an oxidation reaction is carried out at —50°C or lower, a co-solvent such as methylene chloride or THF (tetrahydrofuran) is needed. 

In situ precipitation injectable materials are polymer solutions that precipitate when they come in contact with a non-solvent (physiological fluids) when injected into the body. Usually such polymers are hydrophobic in nature. The polymer solutions are prepared in physiologically tolerant solvents like dimethyl sulfoxide (DMSO) that are also miscible with water. Thus, when the polymer solution is injected into the body, the solvent diffuses and mixes with the physiological fluids while the polymer precipitates out to form the gel as it is not soluble in water. Major examples of this injectable material group include PCL, PLA and PLGA (poly(lactic-co-glycolic) acid) (Coombes et al., 2004, Eliaz and Kost, 2000). 

A very useful group of procedures for oxidation of alcohols to ketones have been developed that involve dimethyl sulfoxide (DMSO) and any one of a number of electrophilic molecules, particularly dicyclohexylcarbodiimide, acetic anhydride, and sulfur trioxide. The initial work involved the DMSO-dicyclo-hexylcarbodiimide system. The utility of the method has been greatest in the oxidation of molecules that are highly sensitive to more powerful oxidants and therefore cannot tolerate alternative methods. The mechanism of the oxidation involves formation of intermediate A by nucleophilic attack of DMSO on the carbodiimide, followed by reaction of this species with the alcohol. A major portion... 

The benzyl group can serve as an alcohol-protecting group when acidic conditions for ether cleavage cannot be tolerated. The benzyl C-O bond is cleaved by catalytic hydrogenolysis," or with sodium in liquid ammonia. Allyl ethers are an alternative to benzyl ethers as a protecting group. Allyl ethers may be isomerized quantitatively by potassium r-butoxide in dimethyl sulfoxide to propenyl ethers, which are quite labile to dilute acid. ... 

Two drawbacks of a-haloacid dehalogenation - i.e., the hydrolytic instability of a-bromoacids in aqueous solvent systems and the limited substrate tolerance of a-haloacid dehalogenases — can be overcome by using anhydrous organic solvents [1828]. Thus, long-chain a-haloacids (which were not accepted as substrates in water) were successfully transformed with good specificity in toluene, acetone or even in dimethyl sulfoxide. 

Dimethyl sulfoxide (Me2SO) at 10-20% increases the yield by two- to threefold in some RNA ligation reactions (9,10). However, in DNA ligation reactions, e.g., with pdNp, Me2SO has been shown to be inhibitory (2). The T4 RNA ligase by itself can tolerate up to 40% Me2SO without any appreciable decrease in activity. 

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