Sodium chloride-Dimethyl sulfoxide

For an improved procedure see Sodium Chloride-Dimethyl sulfoxide, this volume, van Tamelen and Anderson effected dccarbomethoxylation of (1) in 81 % yield by... 

DECARBOMETHOXYLATION l.S-Diaza-bicycIo[4.3.0]nonene-S. Sodium Chloride-Dimethyl sulfoxide. Sodium cyanidc-Dimethyl sulfoxide. 

Sodium-f-Butanol-Tetrahydrofurane, 291 Sodium /-butoxide, 305 Sodium chloride-Dimethyl sulfoxide, 445 Sodium chloroacetate, 275 Sodium N-chloro-p-to/uenesulfonamide, 75, 445-446... 

CYCLOPROPYL KETONES Sodium chloride-Dimethyl sulfoxide. 

CYCLOPROPYL KETONES Sodium Chloride-Dimethyl sulfoxide. 

Secondary Chlorides With a low-boiling chloride such as 2-chlorobutane, a stirred slurry of 30 g (0.61 mole) of sodium cyanide in 150 ml of dimethyl sulfoxide is heated to 90° with a heating mantle, and 0.5 mole of the chloride is slowly added over a period of 30 minutes. The temperature of the refluxing reaction mixture slowly increases as nitrile is formed. Refluxing continues as the temperature slowly rises to 150° after 3 hours reaction time. The flask is then cooled and the reaction mixture is worked up in the same way as for the primary nitriles. With 2-chlorooctane, the sodium cyanide-dimethyl sulfoxide slurry is heated to 130° and 0.5 mole of the chloride added. The reaction mixture is maintained at 135-145° for 1 hour, then cooled, and the product is isolated as above. Examples are given in Table 16.1. 

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. 

Dimethylformamide [68-12-2] (DME) and dimethyl sulfoxide [67-68-5] (DMSO) are the most commonly used commercial organic solvents, although polymerizations ia y-butyrolactoae, ethyleae carboaate, and dimethyl acetamide [127-19-5] (DMAC) are reported ia the hterature. Examples of suitable inorganic salts are aqueous solutioas of ziac chloride and aqueous sodium thiocyanate solutions. The homogeneous solution polymerization of acrylonitrile foUows the conventional kinetic scheme developed for vinyl monomers (12) (see Polymers). 

Vinyl chloride reacts with sulfides, thiols, alcohols, and oximes in basic media. Reaction with hydrated sodium sulfide [1313-82-2] in a mixture of dimethyl sulfoxide [67-68-5] (DMSO) and potassium hydroxide [1310-58-3], KOH, yields divinyl sulfide [627-51-0] and sulfur-containing heterocycles (27). Various vinyl sulfides can be obtained by reacting vinyl chloride with thiols in the presence of base (28). Vinyl ethers are produced in similar fashion, from the reaction of vinyl chloride with alcohols in the presence of a strong base (29,30). A variety of pyrroles and indoles have also been prepared by reacting vinyl chloride with different ketoximes or oximes in a mixture of DMSO and KOH (31). 

Isotope labeling by derivative formation with deuterated reagents is useful for the preparation of analogs such as dg-acetonides, da-acetates, da-methyl ethers, dg-methyl esters, etc. The required reagents are either commercially available or can be easily prepared. (The preparation of da-methyl iodide is described in section IX-F. Various procedures are reported in the literature for the preparation of dg-acetone, da-diazometh-ane57.i63.i73 and da-acetyl chloride. ) These reactions can be carried out under the usual conditions and they need no further discussion. A convenient procedure has been reported for the da-methylation of sterically hindered or hydrogen bonded phenolic hydroxyl functions by using da-methyl iodide and sodium hydroxide in dimethyl sulfoxide solution. This procedure should be equally applicable to the preparation of estradiol da-methyl ether derivatives. 

Base-catalyzed proton abstraction from trimethylsulfoxonium halides (1) with formation of dimethylsufoxonium methylide (2) was described by Corey in 1962. Solutions of (2) in dimethyl sulfoxide are conveniently prepared from the chloride or iodide (1) by stirring with one equivalent of sodium hydride at room temperature. 

Methylsulfinyl carbanion (dimsyl ion) is prepared from 0.10 mole of sodium hydride in 50 ml of dimethyl sulfoxide under a nitrogen atmosphere as described in Chapter 10, Section III. The solution is diluted by the addition of 50 ml of dry THF and a small amount (1-10 mg) of triphenylmethane is added to act as an indicator. (The red color produced by triphenylmethyl carbanion is discharged when the dimsylsodium is consumed.) Acetylene (purified as described in Chapter 14, Section I) is introduced into the system with stirring through a gas inlet tube until the formation of sodium acetylide is complete, as indicated by disappearance of the red color. The gas inlet tube is replaced by a dropping funnel and a solution of 0.10 mole of the substrate in 20 ml of dry THF is added with stirring at room temperature over a period of about 1 hour. In the case of ethynylation of carbonyl compounds (given below), the solution is then cautiously treated with 6 g (0.11 mole) of ammonium chloride. The reaction mixture is then diluted with 500 ml of water, and the aqueous solution is extracted three times with 150-ml portions of ether. The ether solution is dried (sodium sulfate), the ether is removed (rotary evaporator), and the residue is fractionally distilled under reduced pressure to yield the ethynyl alcohol. 

Primary Chlorides Dry sodium cyanide (30 g, 0.61 mole) is added to 150 ml of dimethyl sulfoxide in a flask fitted with a stirrer, reflux condenser, dropping funnel, and thermometer. The thick slurry is heated on a steam bath to 90° and the steam bath is then removed. The halide (0.5 mole of monochloride or 0.25 mole of dichloride) is slowly added to the stirred mixture, causing the temperature to increase immediately. The rate of addition should be adjusted so that the temperature of the reaction does not go above about 160°. After all the halide is added (about 10 minutes) the mixture is stirred for 10 minutes more, or until the temperature drops below 50°. In the preparation of mononitriles, the reaction mixture is then poured into water, and the product is extracted with chloroform or ether. The extract is washed several times with saturated sodium chloride solution then dried over calcium chloride, and the product is distilled. 

The reaction of the aldehyde 174, prepared from D-glucose diethyl dithio-acetal by way of compounds 172 and 173, with lithium dimethyl methyl-phosphonate gave the adduct 175. Conversion of 175 into compound 176, followed by oxidation with dimethyl sulfoxide-oxalyl chloride, provided diketone 177. Cyclization of 177 with ethyldiisopropylamine gave the enone 178, which furnished compounds 179 and 180 on sodium borohydride reduction. 0-Desilylation, catalytic hydrogenation, 0-debenzyIation, and acetylation converted 179 into the pentaacetate 93 and 5a-carba-a-L-ido-pyranose pentaacetate (181). 

B. (3-Bromo-3,3-difluoropropyl)trimethylsilane. A 1-L, four-necked flask is equipped with a mechanical stirrer, thermometer, Claisen adapter, septum inlet, reflux condenser (the top of which is connected to a calcium chloride drying tube), and a solid addition funnel. The flask is charged with (1,3-dibromo-3,3-difluoropropyl)trimethylsilane (78.3 g, 0.25 mol), and anhydrous dimethyl sulfoxide (200 mL), and the solid addition funnel is charged with sodium borohydride (11.5 g, 0.30 mol) (Notes 7 and 8). The stirred solution is warmed to 80°C, and sodium borohydride is added at a rate sufficient to maintain a reaction temperature of 80-90°C (Note 9). Toward the end of the addition, an additional portion of dimethyl sulfoxide (200 mL) is added via syringe to lower the viscosity of the reaction mixture. After the addition is complete, the mixture is cooled in an ice-water bath, diluted with 100 mL of pentane, and cautiously quenched with 12 M hydrochloric acid until no further gas evolution occurs. The mixture is transferred to a separatory funnel and washed with three, 100-mL portions of 5% brine. The pentane extract is dried over calcium chloride and the solvent removed through a 15-cm Vigreux column. Further fractionation yields 41.5 g (72%) of 3-bromo-3,3-difluoropropyltrimethylsilane, bp 139-141 °C (Note 10). 

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).-... 

Displacement of chloride from a neutral triazole has also been reported for example, 5-chloro-l,4-diphenyltriazole reacts with sodium cyanide in dimethyl sulfoxide to give the 5-cyano derivative. ... 

Some 30 years later, Wanzlick s work was reinvestigated by Arduengo et al., who were able to prepare and to isolate the imidazol-2-ylidene IVc (R = adamantyl) in near quantitative yield (Scheme 8.4). The deprotonation of the 1,3-di-l-adamantylimidazolium chloride (4c) was carried out with sodium or potassium hydride, in the presence of catalytic amounts of either f-BuOK or the dimethyl sulfoxide (DMSO) anion. Carbene IVc is thermally stable in the solid state (colorless crystals, mp 240-241 °C). 

By heating 32 in aqueous dimethyl sulfoxide (DMSO), containing sodium chloride, up to 170°C, loss of a methoxycarbonyl group and then -elimination of acetic acid occur to give alkene 33 in 70% yield. From this, carba-pl-L-mannopyranose 34 has been produced by conversion of the ester group to the hydroxymethyl function, hydroboration, and de-O-protection. Thus, the hydroboration step proceeded by cis-addition anti- to the allylic benzyloxy group. 

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