Potassium carbonate-Dimethyl sulfoxide

LACTONES 2,2 -Dipyridyl disulfide. Manganic acetate. Potassium carbonate-Dimethyl sulfoxide. Silver carbonate-Celite. Silver fluoroborate. Sodium hydride. Thallous 2-methylpropane-2-thiolate. 

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),... 

Alcoholic potassium hydroxide or sodium hydroxide are normally used to convert the halohydrins to oxiranes. Other bases have also been employed to effect ring closure in the presence of labile functional groups such as a-ketols, e.g., potassium acetate in ethanol, potassium acetate in acetone or potassium carbonate in methanol.However, weaker bases can lead to solvolytic side reactions. Ring closure under neutral conditions employing potassiunT fluoride in dimethyl sulfoxide, dimethylformamide or A-methyl-pyrrolidone has been reported in the patent literature. 

The use of heterocyclic 1,2,3-amino, cyano, methylthio compounds with DMAD or DEAD in dimethyl sulfoxide in the presence of potassium carbonate yields polycyclic products, for example those shown in Scheme 8 <96H(42)53>. 

An oven-dried flask, with a septum capped nitrogen inlet, was charged with a solution of (G = —0.5) dendn-PAMAM(C02Me)4 [J ] precursor (2.5 g, 6.2 mmol) in anhydrous dimethyl sulfoxide (10 ml). A mixture of Tris (tri-hydroxymethyl aminoethane) (3.76 g, 0.031 mol) and anhydrous potassium carbonate (2.7 g, 0.031 mol) was added to the suspension. The solution was heated in a paraffin oil bath maintained at 40°C for 96 h. After filtration the excess solvent was removed by vacuum pump (10 1 mm Hg, 50°C). The resulting thick, white oil was dissolved in a minimum quantity of distilled water and precipitated with propanone. The suspension was cooled in the freezer, and the solid filtered and dried in a vacuum oven (10 1 mm Hg, 40 °C) to give the hygroscopic terminated dendrimer as a white powder (4.5 g, 95%). 

In a loosely stoppered 1-1. round-bottomed flask are placed 37.5 g. (48 ml.) of <-butyl alcohol, 150 ml. of dimethyl sulfoxide (Note 1), and a Teflon -coated magnetic stirring bar. The solution is heated in an oil bath which is placed on a combination magnetic stirrer-hotplate. When the temperature of the mixture reaches 125-130°, 75 g. (0.67 mole) of alcohol-free potassium -butoxide (Notes 2 and 3) is added, the stopper is replaced loosely, and the mixture is stirred. When all the potassium /-butoxide is in solution, the stopper is removed, 25 g. (0.159 mole, 17 ml.) of bromobenzene is added in one portion to the hot solution, and an air condenser fitted with a dr dng tube is rapidly placed on the flask. The solution immediately turns dark brown, and an extremely vigorous, exothermic reaction occurs. After 1 minute the reaction mixture is poured into 500 ml. of water. The aqueous solution is saturated with sodium chloride and extracted with four 200-ml. portions of ether (Note 4). The ether extract is washed with three 100-ml. portions of water and dried over anhydrous potassium carbonate. The ether is distilled at atmospheric pressure on a steam bath to leave 17-18 g. of crude phenyl /-butyl ether (Note 5). The brown oil is distilled to yield 10-11 g. (42-46%) of pure phenyl /-butyl ether, b.p. 45-46° (2 mm.), m.p. —17 to —16°, 1.4860-1.4890 (Note 6).-... 

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 double bond of 9-allylcarbazoles can be moved into conjugation with the nitrogen by treatment with potassium rcrt-butoxide in dimethyl sulfoxide the cis-prop-l-enyl isomers were formed initially in studies with 9-allyl-carbazole, 9-allyl-3-chlorocarbazole, 9-allyl-3-nitrocarbazole, and 9-allyl-3,6-dichlorocarbazole. " Such isomerizations must proceed via a car-banion produced by proton abstraction from the saturated carbon on nitrogen. Indeed, when the red anion from 9-benzylcarbazole, formed using n-butyllithium, was quenched with deuterium oxide, the 9-CHDPh derivative was obtained. When the anions from 9-ally 1-carbazoles in the series 81... 

A 1-1., three-necked, round-bottomed flask is equipped with an internal thermometer, mechanical stirrer, dropping funnel, and calcium chloride drying tube. The flask is charged with 500 ml. of dimethyl sulfoxide and 15 g. (0.11 mole) of potassium carbonate (Note 1). The mixture is heated to 100°, and a solution of 10.0 g. (0.038 mole) of 11-bromoundecanoic acid (Note 2) in 200 ml. of dimethyl sulfoxide is added dropwise with vigorous stirring over 1... 

Reagent-grade dimethyl sulfoxide and anhydrous potassium carbonate were used. 

The 1,2,6-thiadiazines 571 are prepared from the -diketones 569 and sulfamide 570 in high yields (Scheme 257) <1965M216>. An efficient synthesis of iV-aryl-l,2,6-thiadiazine 1,1-dioxides 573 is based on the cyclization of 3-chloropropyl phenylsulfamide 572 using potassium carbonate in dimethyl sulfoxide (Scheme 258) <2003TL5483, 2003T6051, CHEC-III(9.07.9)385>. 

Other hazardous reactions may occur with carbon (e.g., soot, graphite, activated charcoal), dimethyl sulfoxide, ethylene oxide, chlorine, bromine vapor, hydrogen bromide, potassium iodide + magnesium bromide, chloride or iodide, maleic anhydride, mercury, copper(II) oxide, mercury(II) oxide, tin(IV) oxide, molybdenum(III) oxide, bismuth trioxide, phosphoms trichloride, sulfur dioxide, chromium trioxide. 

Another variation on the same theme is the oxidation of a-bromo ketones by dimethyl sulfoxide in the presence of potassium iodide and sodium carbonate. In situ conversion of the bromo ketone into iodo ketone evidently facilitates the reaction, because it is successful even with secondary a-bromo ketones, with which simple oxidation fails. Depending on the steric environment, the reaction may occur at room temperature, but it may require a temperature of 120 C. Yields range from 71 to 95% (equation 413) [1005. ... 

Other electrolytes that have been applied, are dimethyl sulfoxide/sodium hydride, glycol methyl ether/water/potassium carbonate or acetic acid/potassium carboxylate. ... 

Potassium permanganate. Dimethyl sulfide-Chlorine. Dimethyl sulfoxide. Dimethyl sulfoxide-Chlorine. Dimethylsulf-oxide Sulfur trioxide. Dipyridine chro-mium(VI) oxide. Iodine. Iodine-Potassium iodide. Iodine tris(trifluoroacetate). Iodosobenzene diacetate. Isoamyl nitrite. Lead tetraacetate. Manganese dioxide. Mercuric acetate. Mercuric oxide. Osmium tetroxide—Potassium chlorate. Ozone. Periodic acid. Pertrifluoroacetic acid. Potassium ferrate. Potassium ferricyanide. Potassium nitrosodisulfonate. Ruthenium tetroxide. Selenium dioxide. Silver carbonate. Silver carbonate-Celite. Silver nitrate. Silver oxide. Silver(II) oxide. Sodium hypochlorite. Sulfur trioxide. Thalli-um(III) nitrate. Thallium sulfate. Thalli-um(III) trifluoroacetate. Triphenyl phosphite ozonide. Triphenylphosphine dibromide. Trityl fluoroborate. 

Dimethoxyethane is preferred to dimethyl sulfoxide as solvent for the formyl-ation of ketones with carbon monoxide in the presence of an alkali metal alkoxide. This is due to the fact that DMSO is slightly protic in the presence of a strong base (potassium t-butoxide) and hence not inert. 

Dehydrohalogenation Benzyltrimethylammonium mcsitoate. r-Butylamine. Calcium carbonate. j Uidine. Diazabicyclo[3.4.0]nonene-5. N.N-Dimethylaniline (see also Ethoxy-acetylene, preparation). N,N-Dimelhylformamide. Dimethyl sulfoxide-Potassium r-but-oxide. Dimethyl sulfoxide-Sodium bicarbonate. 2,4-Dinitrophenylhydrazine. Ethoxy-carbonylhydrazine. Ethyldicyclohexylamine. Ethyidiisopropylamine. Ion-exchange resins. Lithium. Lithium carbonate. Lithium carbonate-Lithium bromide. Lithium chloride. Methanolic KOH (see DimethylTormamide). N-PhenylmorphoKne. Potassium amide. Potassium r-butoxide. Pyridine. Quinoline. Rhodium-Alumina. Silver oxide. Sodium acetate-Acetonitrile (see Tetrachlorocyclopentadienone, preparation). Sodium amide. Sodium 2-butylcyclohexoxide. Sodium ethoxide (see l-Ethoxybutene-l-yne-3, preparation). Sodium hydride. Sodium iodide in 1,2-dimethoxyethane (see Tetrachlorocyclopentadienone, alternative preparation) Tetraethylammonium chloride. Tri-n-butylamine. Triethylamine. Tri-methyiamine (see Boron trichloride). Trimethyl phosphite. 

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