Sulfoxides solvent

An explosion was experienced dining work up of an epoxide opening reaction involving acidified sodium azide in a dichloromethane/dimethyl sulfoxide solvent. The author ascribes this to diazidomethane formation from dichloromethane [1]. A second report of an analoguous accident, also attributed to diazidomethane, almost certainly involved hydrogen azide for the cold traps of a vacuum pump on a rotary evaporator were involved this implies an explosive more volatile than dichloromethane. It is recommended that halogenated solvents be not used for azide reactions [2]. 

Dolfini [89] found that, when equimolar ratios of aziridine (ethylenimine) reacts with dimethyl acetylene dicarboxylate in methanol at room temperature, a 67 % yield of the trans and a 33 % yield of the cis product are obtained. In dimethyl sulfoxide solvent, 95% of the cis and 5% of the trans ester are obtained (Eq. 32). 

Solvents shown were those used for the determination of kSSN kH20,SN determined in H2O, unless otherwise specified. Numbers in parentheses are the volumetric proportions for solvent mixtures. Abbreviations are as follows MeOH methanol ace acetone diox dioxane EtOH ethanol DMF dimethylformamide DMSO dimethyl sulfoxide. Solvent not specified when value of log(ks/kH2o)sN was estimated solely from a correlation equation (e.g., those provided in (181 and (22)). 

The mobile phases used in reversed-phase chromatography are based on a polar solvent, typically water, to which a less polar solvent such as acetonitrile or methanol is added. Solvent selectivity is controlled by the nature of the added solvent in the same way as was described for normal-phase chromatography solvents with large dipole moments, such as methylene chloride and 1,2-dichloroethane, interact preferentially with solutes that have large dipole moments, such as nitro- compounds, nitriles, amines, and sulfoxides. Solvents that are good proton donors, such as chloroform, m-cresol, and water, interact preferentially with basic solutes such as amines... 

The kinetics of polycondensation hy nucleophilic aromatic substitution in highly polar solvents and solvent mixtures to yield linear, high molecular weight aromatic polyethers were measured. The basic reaction studied was between a di-phenoxide salt and a dihaloaromatic compound. The role of steric and inductive effects was elucidated on the basis of the kinetics determined for model compounds. The polymerization rate of the dipotassium salt of various bis-phenols with 4,4 -dichlorodiphenylsulfone in methyl sulfoxide solvent follows second-order kinetics. The rate constant at the monomer stage was found to be greater than the rate constant at the dimer and subsequent polymerization stages. 

Silver salts are also utilized to perform nucleophilic additions to disulfide bonds to yield sulfenamides (146). If alkyl halides are treated with stoichiometric AgBF4 in dimethyl sulfoxide solvent (DMSO, solvent), the corresponding aldehydes/ ketones will form in good yields. This reaction is an alternative to the well-known Swern oxidation (147). In addition, silver can drive the formation of dialkylper-oxonium ions from alkyl halides, which then oxidizes sulfoxides or sulfides (148,149). In the presence of AgN03, sulfides can be oxidized into a-chloro sulfoxides by SO2CI2 (Fig. 36) (150). 

Dimethyl sulfoxide (solvent) Dimethyl sulfoxide (ligand)... 

Acyloins are sometimes formed in moderate yield when 1,2-disubstituted epoxides are treated with BFj in dimethyl sulfoxide solvent. A curious report of highly temperature dependent nonoxidative rearrangement of 2,3-epoxycyclododecanone indicates that a 1,2-dione is formed at 85 °C, whereas a 1,3-dione is the product at 150 °C. All of these applications require heating, since the Lewis acidity of BF3 is strongly attenuated in dimethyl sulfoxide. O ... 

DMF dmso DMSO dpae dpam dppb dppe dppm dppp ET Hdbpz Hdcmpz Hdfmpz Hdmepz Hdmpz Hdppz Hmpz Hpz Hpz Htmpz IR nbd NMR phen /V./V-Dimethylformamide Dimethyl sulfoxide (ligand) Dimethyl sulfoxide (solvent) 1.2- Bis(diphenylarsino)ethane Bis(diphenylarsino)methane 1.4- Bis(diphenylphosphino)butane 1.2- Bis(diphenylphosphino)ethane Bis(diphenylphosphino)methane 1.3- Bis(diphenylphosphino)propane Electron transfer 3.5- Di-ferf-butylpyrazole 3.5- Dicarbomethoxypyrazole 3.5- Bis(trifluoromethyl)pyrazole 3(5),4-Dimethyl-5(3)-ethylpyrazole 3.5- Dimethylpyrazole 3.5- Diphenylpyrazole 3(5)-Methylpyrazole Pyrazole A general pyrazole 3.4.5- Trimethylpyrazole Infrared spectroscopy Norbomadiene (bicyclo-[2.2.1. ]-heptadiene) Nuclear magnetic resonance 1,10-Phenanthroline... 

For a procedure for Wolff-Kishner reduction at room temperature, see Dimethyl sulfoxide, solvent effects. 

Sulfoxide Solvent Lewis Acid Tempe- rature Time Diastereo- selectivity Total Yield (%)... 

In a monovalent thallium complex, a V(T1,F) coupling was found to be extremely solvent dependent. In fact, at room temperature in chloroform a coupling of 850 Hz was measured, which reduced to 0 Hz in methanol, acetonitrile and dimethyl sulfoxide, solvents that promote dissociation. ... 

Petrus L., Gray D.G., BeMiUer J.N., Homogeneous alkylation of cellulose in Uthium chloride/dimethyl sulfoxide solvent with dimsyl sodium activation. A proposal for the mechanism of cellulose dissolution in Uthium chloride/DMSO, Carbohyd. Res., 268, 1995, 319-323. 

Various ratios of AA, IA and NVP monomers were copolymerized in water with potassium persulfate initiator ( 2 % by wt of combined monomers) with polymerization run under nitrogen for 9-10 hr at 95 °C. The copolymers prepared (Table 2) were recovered in high yields, using standard freeze-drying techniques. Several poly(AA-co-lA) and poly(AA-co-NVP) were also prepared for the study. For purification, the copolymers were dissolved in methyl alcohol and precipitated from diethyl ether, followed by drying under vacuum. The IR spectrum of the copolymers were obtained from cast films, using a MID AC FT IR Spectrometer. NMR ( H and C) spectra were obtained on a Bruker AM 250 MHz NMR analyzer, using deutrated methyl sulfoxide solvent and trimethylsilane (TMS) reference (Table I). 

The alpha effect, the enhanced reactivity of nucleophiles with a lone pair of electrons on an adjacent center, has been investigated in reactions with substituted phenyl-phenyl carbonates in water/DMSO (dimethyl sulfoxide) solvent. The enhanced reactivity of oxi-mate ions, which are alpha nucleophiles, was attributed to solvation effects in the ground state rather than to transition state effects. ... 

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