Solvents Tetramethylene sulfone

Abstract The miscibility behavior in blends of polyethersulfone (Victrex PES) with the polyimide PI 2080, (the condensation product of 3,3, 4,4 -benzophenone tetracarboxylic dianhydride [BDTA] and a 4 1 mixture of 2,4-toluene diisocyanate and 4,4 -diphenylmethane diisocyanate) or with the polyimide XU 218 (the condensation product of BDTA and 5(6)-amino-l-(4 -aminophenyl)-l,3,3 -trimethylindane) was investigated using differential scanning calorimetry, dynamic mechanical analysis and thcmiogravimetric analysis. The effects of solvents (dimethylacetamide, tetramethylene sulfone, dimethyl sulfoxide and l-methyl-2-pyrrolidone) on miscibility were studied and one solvent, tetramethylene sulfone was found to have a plasticizing effect. In the absence of solvent, the equilibrium phase boundary for these blends was in the experimentally inaccessable region below the Tg-composition line. The phase boundary at zero solvent concentration was obtained by extrapolation using data collected in the presence of the plasticizer. 

Nitrations can be performed in homogeneous media, using tetramethylene sulfone or nitromethane (nitroethane) as solvent. A large variety of aromatic compounds have been nitrated with nitronium salts in excellent yields in nonaqueous media. Sensitive compounds, otherwise easily hydroly2ed or oxidized by nitric acid, can be nitrated without secondary effects. Nitration of aromatic compounds is considered an irreversible reaction. However, the reversibihty of the reaction has been demonstrated in some cases, eg, 9-nitroanthracene, as well as pentamethylnitrobenzene transnitrate benzene, toluene, and mesitylene in the presence of superacids (158) (see Nitration). 

As normally polymerized, PVF melts between IH5 and 210 °C and contains 12 18% inverted monomer units ft is normally considered a thermoplastic, but because of its instability above its melting point, it cannot be processed by conventional thermoplastic techniques Instead it is generally extruded into films in a solvent swollen (organosol) form and the solvent is subsequently evaporated and recovered Such films can be onented further to achieve specific mechanical properties PVF films are exceptionally weather and radiabon resistant considenng their modest fluonne content PVF is insoluble below 100 °C but, at higher temperatures, it dissolves in polar solvents like amides, ketones, tetramethylene sulfone, and tetramethylurea Resistance to acids and bases at room temperature IS good [1, 29 ... 

The importance of the solvent, in many cases an excess of the quatemizing reagent, in the formation of heterocyclic salts was recognized early. The function of dielectric constants and other more detailed influences on quatemization are dealt with in Section VI, but a consideration of the subject from a preparative standpoint is presented here. Methanol and ethanol are used frequently as solvents, and acetone,chloroform, acetonitrile, nitrobenzene, and dimethyl-formamide have been used successfully. The last two solvents were among those considered by Coleman and Fuoss in their search for a suitable solvent for kinetic experiments both solvents gave rise to side reactions when used for the reaction of pyridine with i-butyl bromide. Their observation with nitrobenzene is unexpected, and no other workers have reported difficulties. However, tetramethylene sulfone, 2,4-dimethylsulfolane, ethylene and propylene carbonates, and salicylaldehyde were satisfactory, giving relatively rapid reactions and clean products. Ethylene dichloride, used quite frequently for Friedel-Crafts reactions, would be expected to be a useful solvent but has only recently been used for quatemization reactions. ... 

Liquid solvents are used to extract either desirable or undesirable compounds from a liquid mixture. Solvent extraction processes use a liquid solvent that has a high solvolytic power for certain compounds in the feed mixture. For example, ethylene glycol has a greater affinity for aromatic hydrocarbons and extracts them preferentially from a reformate mixture (a liquid paraffinic and aromatic product from catalytic reforming). The raffinate, which is mainly paraffins, is freed from traces of ethylene glycol by distillation. Other solvents that could be used for this purpose are liquid sulfur dioxide and sulfolane (tetramethylene sulfone). 

Starting materials which are only sparingly soluble in water may require solvents that are either partially or entirely organic. Diazotization can either be carried out as usual with an aqueous sodium nitrite solution, or alternatively with nitrosylsul-furic acid or an organic nitrite. Appropriate solvents must be stable to the reactants. Examples include aromatic hydrocarbons, chlorohydrocarbons, glycol ethers, nitriles, esters, and dipolar aprotic solvents, such as dimethyl formamide, dimethyl sulfone, tetramethylene sulfone, tetramethyl urea, and N-methylpyrroli-done. 

In most other cases the relationship will allow the approximate prediction of the half-wave potentials of a given ion in a solvent of given donicity by interpolation. It may be expected that E jy2 for a certain metal ion in tetramethylene sulfone (DN = 14.8) will be similar to that in PDC (DN = 15.1), benzylcyanide (DN = 15.1) or ethylene sulfite (DN = 15.3). Likewise, the half-wave potentials are expected to be similar in nitrobenzene (DN = 4.4) and nitromethane (DN = 2.7). In an analogous manner the half-wave potentials may be predicted in methyl acetate, diethylether, pyridine, and various other solvents. 

A heterogeneous mixture of diethyl chloromalonate (5 1.95 g, 10 mmol) and spray-dried KF (3.00 g, 50 mmol) in tetramethylene sulfone (30 mL) was stirred for 3h at 100-120°C, and then bcnzaldehyde (1.60 g, 15 mmol) was added to the mixture. After stirring for 10 h at 100 120 C, the mixture was poured into H20 and the product formed was extracted with Et20. After removal of the solvent, the residue was subjected to distillation yield 1.13 g (58%) bp 121-123 DC/8Torr. 

Systematic work has been carried out on the replacement of chlorines in tetra- and pen-tachloropyridines with fluorine.117,118 Potassium fluoride has been used as the reagent with (tetramethylene sulfone, A-methyl-2-pyrrolidone) and without (autoclave) solvent. Besides per-fluoropyridine, a mixture of chlorofluoropyridines has been obtained. 

Formamidc has been found to be a very suitable solvent for fluoride displacement reactions on optically active substrates leading to more reduced racemization that is in comparison to other aprotic solvents like tetramethylene sulfone, l,3-dimethyl-3,4,5,6-tetrahydropyrimidin-2(l/7)-one etc.146 Formamide has a high polarizability favoring SN2 reactions and a high polarity147 rendering potassium fluoride sufficiently soluble in the reaction mixture. Although the reaction rate is reduced, the less polar solvents A-methylformamide, acetamide or A-methyl-acetamide can also be used as solvents for the reaction. 

Other solvents, such as dimethyl sulfone, tetramethylene sulfone, or acetic aoid, have been Btated 4 to give polyglycoses containing no oxymethylene groups. 

Other solvents may also be used with similar effects. Isopropyl alcohol has been used for fractionating a polyglucose.72 Examination of the fractions revealed that fractionation according to viscosity and immunological reactivity had occurred.240 The excellent solvent properties of methyl sulfoxide,241 tetramethylene sulfone, pyridine, N, TV-dimethylformamide, and formamide may also prove useful. 

Carbon dioxide removal by reactive absorption in amine solutions is also applied on the commercial scale, for instance, in the treatment of flue gas (see later in this chapter). Another possible application field of the technique is gas desulfurization, in which H2S is removed and converted to sulfur by means of reactive absorption. Aqueous solutions of ferric chelates (160-162) as well as tetramethylene sulfone, pyridine, quinoline, and polyglycol ether solutions of S02 (163,164) have been proposed as solvents. Reactive absorption can also be used for NOx reduction and removal from flue or exhaust gases (165,166). The separation of light olefins and paraffins by means of a reversible chemical com-plexation of olefins with Ag(I) or Cu(I) compounds in aqueous and nonaqueous solutions is another very interesting example of reactive absorption, one that could possibly replace the conventional cryogenic distillation technology (167). 

Solvents used to extract the benzene include tetramethylene sulfone (Fig. 2), diethylene glycol, IV-methylpyrrolidinone process, dimethylfor-mamide, liquid sulfur dioxide, and tetraethylene glycol. 

Acceptor numbers of various solvents are also listed in Table 3. The values range from zero, for the reference solvent -hexane, to about 130, for trifluoro-methane sulfonic acid. For instance, the acceptor number of aliphatic alcohols varies between 27 and 41 (methanol). Within the group of dipolar aprotic solvents there are considerable differences in acceptor properties. Solvents such as propylenecarbonate, tetramethylene-sulfone, acetonitrile, dimethylsulfoxide, or nitromethane are stronger acceptors than solvents such as acetone, A-methylpyrroli-done, or dimethylacetamide. The acceptor strengths of amine solvents vary considerably with the degree of substitution. For instance, triethylamine has no acceptor properties. 

Earlier methods of preparing 2,2,4,4-tetrakis(trifluoromethyl)-l,3-dlthletane (hexafluorothioacetone dimer, HFTA dimer) include the reaction of hexafluoropropene (HEP) and sulfur over a carbon bed at 425< C,3 and the reaction of HFP and sulfur in tetramethylene sulfone at 120°C 1n the presence of potassium fluoride (autoclave). Dimethylformamide appears to be a far superior solvent for this reaction, permitting the use of atmospheric pressure and modest temperatures, as well as affording a cleaner product. 

The reduction of the capacity factors with increasing organic modifier concentration in the eluent was weaker when methanol was used compared to acetonitrile, and this was attribnted to its lower polarity [5]. Even if methanol or acetonitrile are the most common organic modifiers, an unusual solvent, tetramethylene oxide [16], was recently tested in the IPC of sulfides and aromatic sulfonated compounds and proved to play an important role in adjusting retention. 

The commonly used solvents other than water are as follows. For the anolyte MeOH, MeC02H, MeCN, CH2CI2, MeN02, tetramethylene sulfone, pyridine, THF, Me(XH2CH20Me and propylene carbonate, For the catholyte MeCN, DMF, Me2 NCOMe, Me2SO, HMPA, A -methylpyrrolidone, THF, di-oxane, propylene carbonate, Me0CH2CH20Me, MeOH, MeC02H and NH3. 

The recognition that polar solvents such as MeCN, tetramethylene sulfone, benzonitrile, and others greatly increase the activity of the alkali metal fluorides NaF and KF has led to their widespread use in metathesis reactions. Potassium fluoride is more active than NaF but the latter is easily dried and does not readily absorb H2O. Many fluorinations are readily accomplished by refluxing the halide with excess NaF in the solvent in standard glass apparatus or by heating under autogenous pressure in an autoclave. Some examples of useful fluorinations are shown in equations (23 -28). It was recently found that the reactivity of KF is enhanced when used in ionic liquids. ... 

Figure 14.1. Equilibria in a ternary system, type 1, with one pair of partially miscible liquids A = 1-hexene, B = tetramethylene sulfone, C = benzene, at 50°C (R.M. De Fre, thesis, Gent, 1976). (a) Equilateral triangular plot pointP is at 20% A, 10% B, and 70% C. (b) Right triangular plot with tielines and tieline locus, Ihe amount of A can be read off along the perpenicular to the hypotenuse or by difference, (c) Rectangular coordinate plot with tieline correlation below, also called Janecke and solvent-free coordinates.

Nitration. Whereas aryl nitriles have been mononitrated by conventional methods, dinitration has not been achieved because the forcing conditions required effect hydrolysis (and oxidation) of the nitrile group. In contrast, mono- and dinitration can be carried out with nitronium telrafluoroborate in anonaqueous, acid-free system where the only acid originates from the proton elimination during nitration. The solvent used, tetramethylene sulfone or acetonitrile (both water-soluble), is sufficiently basic to keep the acid at a concentration below the level needed to effect detectable hydrolysis (or oxidation). 

Uses. Tetramethylene sulfone has high solvent power for aromatics and has been used extensively by Olah and co-workers for Friedel-Crafts type nitrations and for studies of the mechanism of nitronium tetrafluoroborate nitration of alkyl-benzenes and halobenzenes in homogeneous solution. It is a superior solvent for quaternization of tertiary amines with alkyl halides, since it has a high dielectric constant and does not enter into side reactions observed with nitrobenzene and dimethylformamide. For example in the synthesis of the acridizinium salt (3), Bradsher and Parham effected quaternization of (1) with benzyl bromide in tetramethylene sulfone at room temperature in excellent yield. Several other salts analagous to (2) were obtained in good yield and in crystalline form with use of tetramethylene sulfone, whereas with other solvents the products were colored... 

Solvent effects Birch reduction. 1,2-Dimethoxyethane (Glyme) and Dimethyl ether (see Naphthalene-Sodium), Dimethylformamide. Dimethyl sulfone. Dimethyl sulfoxide. Diphenyl sulfoxide. Ethylene glycol. N-EthylmorphoUne. Hexamethylphosphoric triamide. Methylal. Methylene chloride. Methyl ethyl ketone. N-Methyl-2-pyrrolidone. Nitrometbane. Nitrosyl chloride. Phenetole. Tetrahydrofurane. Tetramethylene sulfone. Tetramethylene sulfoxide. Triethanolamine. Triethyl phosphate. Trifluoroacetic acid,... 

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