Dimethyl sulfolane

Dimethyl sulfolane 0 50 P Chlor For hydrocarbons, inorganic and organometallic compounds... 

Inorganic compounds (includes organometallic compounds) Hydrocarbons C,-C5 (aliphatic) n-Decane di-n-decyl phthalate dimethyl sulfolane neopentyl glycol succinate 1,2,3-tris (2-cyanoethoxy) propane SE-30 (methyl silicone phases) Carbowax 400-1500 most branched and substituted phthalate, sebacate, succinate, and adipate phases octadecane squalane (boiling point separations) methyl silicones... 

Figure 5. Dependence of selectivity on temperature. System hexane (1)-benzene (2). nitrobenzene, A acetonitrile, + furfural, V dimethyl sulfolane,...

Facilitating the introduction of the metal carboxylates into the epoxy compositions is possible by complexing them with such volatile, coordinating, and electron-donating solvents as dimethyl formamide, dimethyl sulfoxide, dimethyl sulfolane, tetramethyl urea, dimethyl acetamide, methylcaprolactam, or methyl pyrrollidone. These solvents evaporate when applied to a surface to reactivate the salt catalysts by the formation of the occupied coordination sites, which results in the reaction of the epoxy oligomers with the carboxylic acid anhydrides [214]. 

Column 2.1 m by 3.2-mm (7 ft by >/8-in.) outside diameter steel packed with 20 % diisopropyl phthalate on 60/80 mesh NAW Chromosorb P followed by 1S.2 m by 3.2-mm (SO ft by Vs-in.) outside diameter stainless steel packed with 20 % dimethyl sulfolane on 60/80 mesh NAW Chromosorb P. 

The preparation of fluoroaromatics by the reaction of KF with perhaloaromatics, primarily hexachloroben2ene, has received considerable attention. Two methods were developed and include either the use of an aprotic, polar solvent, such as /V-methy1pyrro1idinone (8), or no solvent (9). These methods plus findings that various fluoroaryl derivatives are effective fungicides (10) prompted development of a commercial process for the production of polyfluoroben2enes (11). The process uses a mixture of sodium and potassium fluorides or potassium fluoride alone in aprotic, polar solvents such as dimethyl sulfoxide or sulfolane. 

Nucleophilic Substitution Route. Commercial synthesis of poly(arylethersulfone)s is accompHshed almost exclusively via the nucleophilic substitution polycondensation route. This synthesis route, discovered at Union Carbide in the early 1960s (3,4), involves reaction of the bisphenol of choice with 4,4 -dichlorodiphenylsulfone in a dipolar aprotic solvent in the presence of an alkaUbase. Examples of dipolar aprotic solvents include A/-methyl-2-pyrrohdinone (NMP), dimethyl acetamide (DMAc), sulfolane, and dimethyl sulfoxide (DMSO). Examples of suitable bases are sodium hydroxide, potassium hydroxide, and potassium carbonate. In the case of polysulfone (PSE) synthesis, the reaction is a two-step process in which the dialkah metal salt of bisphenol A (1) is first formed in situ from bisphenol A [80-05-7] by reaction with the base (eg, two molar equivalents of NaOH),... 

The influence of the solvent on the oxidation of film under conformational relaxation control is illustrated in Fig. 47, which shows chronoamperograms obtained by steps from -2000 to 300 mV vs. SCE at room temperature (25°C) over 50 s in 0.1 M LiC104 solutions of different solvents acetonitrile, acetone, propylene carbonate, (PC), dimethyl sulfoxide (DMSO), and sulfolane. Films were reduced over 120 s in the corresponding background solution. Despite the large differences observed in the relative shape of the curves obtained in different solvents, shifts in the times for the current maxima (/max) are not important. This fact points to a low influence of the solvent on the rate at which confor-... 

Alkyl esters are efficiently dealkylated to trimethylsilyl esters with high concentrations of iodotrimethylsilane either in chloroform or sulfolane solutions at 25-80° or without solvent at 100-110°.Hydrolysis of the trimethylsilyl esters serves to release the carboxylic acid. Amines may be recovered from O-methyl, O-ethyl, and O-benzyl carbamates after reaction with iodotrimethylsilane in chloroform or sulfolane at 50—60° and subsequent methanolysis. The conversion of dimethyl, diethyl, and ethylene acetals and ketals to the parent aldehydes and ketones under aprotic conditions has been accomplished with this reagent. The reactions of alcohols (or the corresponding trimethylsilyl ethers) and aldehydes with iodotrimethylsilane give alkyl iodides and a-iodosilyl ethers,respectively. lodomethyl methyl ether is obtained from cleavage of dimethoxymethane with iodotrimethylsilane. 

Parker37 defined class 4 as solvents "which cannot donate suitable labile hydrogen atoms to form strong hydrogen bonds with an appropriate species and proposed the designation dipolar aprotic solvents he extended their range down to s > 15 and quoted as examples acetone, acetonitrile, benzonitrile, dimethylformamide, dimethyl sulphoxide, nitrobenzene, nitromethane (41.8) and sulfolane (tetramethylene sulphone) (44), where e varies from 21 to 46.5, and the dipole moment p from 2.7 to 4.7 debye. 

Aromatic nucleophilic radiofluorinations are usually performed in aprotic polar solvents, such as dimethyl sulfoxide (DMSO), sulfolane or dimethylacetamide, and often under basic conditions (because of the presence of Kryptofix-222 / potassium carbonate). Completion of the p F]fluoride incorporation often requires moderate to high temperatures (100-170 °C) for 10-30 min. Microwave technology can be a successful application here, resulting in improved yields and shorter reaction times [29,170-173],... 

The mono-a-sulfonyl carbanion of sulfolane can be prepared using ethylmagnesium bromide as the base. Condensation of this anion with benzaldehyde gives a mixture of threo and erythro products (77T2019). When sulfolane is treated with n -butyllithium, the dianion is formed quenching with methyl iodide gives the 2,5-dimethyl derivative. 

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