Sulfolane pressure

A slurry of pure calcium fluoride in a solution of potassium fluoride in methanol is slowly evaporated to dryness (KF CaF molar ratio of 1 5) for ca 1 h at 80 °C under reduced pressure Fluonnation of benzyl bromide for 2 h at 120 °C in sulfolane gives 74% yield (92% conversion), compared with 36% with potassium fluonde alone... 

FVP of the aza-bicyclic sulfone 236 at 700°C and 8xl0 2mbar resulted in 3//-pyrrolizin-3-one 237 <2004TL3889>. At same temperature and lower pressure, that is, 4 x 10-2 mbar, the same sulfone affords a mixture of 237 and vinyl pyrrole 238 in 44% and 27% yield, respectively. The latter was the only product obtained when the thermolysis of 236 was performed in a sealed tube in sulfolane. This result and others led Pinho e Melo et al. <2005JOC6629> to suggest the plausible eight-step mechanism shown in Scheme 61. 

Sulfolane plus di-isopropanola-mine Shell Sulfinol 110 Atm-1000 higher pressures favored Yes, <4 ppmv COS, mercaptans, total sulfur <16 ppmv... 

Steele, W.V., Chirico, R.D., Knipmeyer, S.E., and Nguyen, A. Vapor pressure, heat capacity, and density along the saturation line, measurements for cyclohexanol, 2-cyclohexen-l-one, 1,2-dichloropropane, 1,4-di-ferf-butyl benzene, (+)-2-ethyl-hexanoic acid, 2-(methylamino)ethanol, perfluoro-n-heptane, and sulfolane, / Chem. Eng. ilafa, 42(6) 1021-1036,1997a. 

In the industrial process [12] 1,3-butadiene and water are reacted at 60-80 °C in an aqueous sulfolane solvent in the presence of triethylamine hydrogencarbonate under 10-20 bar CO2 pressure. The reaction yields linear telomers mainly, with a 90-93 % selectivity to 2,7-octadien-l-ol together with 4-5 % l,7-octadien-3-ol. Most of the products are removed from the reaction mixture by extraction with hexane, and the aqueous sulfolane phase with the rest of the products, the catalyst and the ammonium bicarbonate is... 

Fig. 5. Plot of log(rates) vs. log(pressure) for rhodium-catalyzed CO hydrogenation. Reaction conditions 75 ml sulfolane, 3 mmol Rh, 1.25 mmol pyridine, H2/CO = 1, 240 C, 4 hr (96). Total rate includes rates to methanol, methyl formate, ethanol, ethylene glycol monoformate, and propylene glycol ( ) total ( ) methanol ( ) ethylene glycol. Open figures are for an experiment with H2/CO = 0.67.

Studies of I /Ru stoichiometry previously discussed and shown in Fig. 20 suggest that these two complexes, or at least a catalyst composition of the same stoichiometry, are present during catalysis. Studies of active solutions during catalysis by high-pressure infrared spectroscopy have also confirmed the presence of these complexes (191). Under 544 atm of H2/CO at 230°C in sulfolane solvent, the infrared absorptions for the carbonyl ligands of both complexes are observed clearly. No other carbonyl absorptions are evident. Samples have also been withdrawn from catalytic reactions and cooled immediately to low temperature before analysis by infrared spectroscopy these solutions also are found to contain only [HRu3(CO)j J and [Ru(CO)3I3]. ... 

In a mixture of 70% HF/ pyridine (50 mL) and sulfolane (30 mL) was dissolved I2 (7.2 g, 0.03 mol). Cyclohexene (2.6 g, 0.03 mol) dissolved in sulfolane (30 mL) was then added over 10 min at rt. The mixture was stirred for 20 min and was then poured into ice water and extracted with Et20. The ethereal layer was washed with H20. aq NaHC03, H20 again and dried (Na2S04). After evaporation of Et20 and unreacted cyclohexene, pure t-fluoro-2-iodocyclohexane was obtained by distillation under reduced pressure yield 4.9 g (60%) bp 73-75 C/10 Torr. 

Figure 3 presents kinetic curves for the formation of 2-phenylpyrrole (Scheme 2) at 96°C and atmospheric C2H2 pressure in various solvents such as DMSO, HMPA, l-methyl-2-pyrrolidone, sulfolane, polyethyleneglycol (PEG) with Mm = 1000, and tetramethylurea [89KGS770]. DMSO is confirmed to possess a specific catalytic effect in this reaction, which is much superior to that of HMPA, l-methyl-2-pyrrolidone, and tetramethylurea. According to their capability to catalyze the formation of 2-phenylpyrrole from acetophenone oxime and acetylene, the solvents under consideration are arranged in the following order DMSO > HMPA l-methyl-2-pyrrolidone > sulfolane > PEG > tetra-... 

The reaction was carried out in dioxane, HMPA, and sulfolane as well as in mixtures of dioxane-DMSO (5 1 by volume) and water-DMSO (1 2) at 100-140°C with alkali metal (Li, Na, K, Rb, Cs) hydroxides, tetrabu-tylammonium hydroxide, and rubidium chloride examined as catalysts. All tests were run in an autoclave (1 L) at an initial acetylenic pressure of 12 atm. The most significant effect on the yield of 1-ethynylcyclo-hexanol (110) is that of the catalyst and the solvent. According to their diminishing efficiency, the catalysts examined are arranged as follows KOH RbOH > (Bu4)NOH > LiOH RbCl failed to catalyze the reaction and in the presence of CsOH, resinification was observed. The alcohol 110 is formed most readily in aqueous DMSO, dioxane being next in efficiency (with account for the yield based on the oxime consumed). Addition of DMSO to dioxane does not improve the yield of 110, and only trace amounts of this compound were obtained in HMPA and sulfolane. 

The solvents used for electroanalytical determinations vary widely in their physical properties liquid ranges (e.g., acetamide, N-methyl-acetamide and sulfolane are liquid only above ambient temperatures), vapour pressures (Table 3.1), relative permittivities (Table 3.5), viscosities (Table 3.9), and chemical properties, such as electron pair and hydrogen bond donicities (Table 4.3), dissolving ability of the required supporting electrolyte to provide adequate conductivity, and electrochemical potential windows (Table 4.8). A suitable solvent can therefore generally be found among them that fits the electroanalytical problem to be solved. 

The Shell Sulfinol Process is used for removal of acidic constituents such as H2S, CO2, COS, etc. from a gas stream. Improved performance over other processes is due to the use of an organic solvent, Sulfolane (tetrahydrothiophene dioxide), mixed with an aqueous alkanolamine. Relative proportions of Sulfolane, alkanolamine, and water, as well as the operating conditions, are tailored for each specific application. Simultaneous physical and chemical absorption under feed gas conditions is provided by this Sulfinol solvent. Regeneration is accomplished by release of the acidic constituents at near atmospheric pressure and a somewhat elevated temperature. The flow scheme (Figure 4) is very similar to that of an aqueous alkanolamine system since it involves only absorption, regeneration and heat exchange under typical alkanolamine treater conditions. 

Thiophene 1,1-dioxide with a shielded sulfur atom was hydrogenated without difficulty to the tetrahydro derivative, sulfolane, over palladium catalyst in acetic acid at room temperature and atmospheric hydrogen pressure (eq. 12.121).249... 

The process reported here uses a clever combination of the factors that promote catalyst life and efficiency. The soluble phosphine or its phosphonium salt, used in a molar excess of about 50 over palladium, stabilizes the palladium complex in aqueous solution the sulfolane-water solution ensures the solubility of the reactants, while extraction with hexane under CO2 pressure recovers the product with only small contamination by palladium, phosphorus or nitrogen. The phosphine or its phosphonium salt and the ammonium bicarbonate remain in the aqueous solution. Since the TON is good and the solution can be recycled, consumption of palladium is very low. 

HP he study of the behavior of electrolytes in mixed solvents is currently arousing considerable interest because of its practical and fundamental implications (1). Among the simpler binary solvent mixtures, those where water is one component are obviously of primary importance. We have recently compared the effects of small quantities of water on the thermodynamic properties of selected 1 1 electrolytes in sulfolane, acetonitrile, propylene carbonate, and dimethylsulfoxide (DMSO). These four compounds belong to the dipolar aprotic (DPA) class of solvents that has received a great deal of attention (2) because of their wide use as media for physical separations and chemical and electrochemical reactions. We interpreted our vapor pressure, calorimetry, and NMR results in terms of preferential solvation of small cations and anions by water and obtained... 

Materials. Sulfolane (99%purity) (Aldrich) was treated with calcium hydride and distilled under reduced pressure. The freshly prepared solvent had a specific conductivity of 1.0 X 10 7 O"1 cm"1 and a residual water content of 8 X 10"3M as determined by Karl Fisher titration. Conductivity water and reagent grade ether (Baker) were used. Glacial acetic acid (CIL), trifluoroacetic acid (Baker), and trifluoro-methanesulfonic acid (3M) were used as received. All these acids had a minimum purity of 99.5% as determined by titration with standard sodium hydroxide. Methanesulfonic acid (Eastman), distilled under reduced pressure, had a purity of 99.6%. Sulfolane solutions of these acids were prepared by weight, and the acid concentrations were checked by acidimetry after the samples were flooded with water. The solutions... 

Figure 1. Vapor pressure of sulfolane solutions of electrolytes as a function of water concentration at 30°C (O), sulfolane (A),...

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