Sodium trifluoromethanesulfonate

Sodium trifluoromethanesulfonate (triflate) was prepared from trifluoromethanesulfonic acid (Aldrich Chemical Company, Inc.) as follows A solution of 26.5 g (0.66 mol) of sodium hydroxide in 50 mL of water was added dropwise to 100 g (0.67 mol) of triflic acid chilled in an ice bath. The solution was concentrated to dryness with a rotary evaporator, and the residual solid was recrystallized from 65 mL of acetonitrile. The collected solid was dried at 80°C under vacuum for 24 hr to give 90 g of pure sodium triflate. 

Perfluorosulfonic acids may be used similarly [299]. They may be purified by distillation and treatment with H2O2 [300]. Trifluoromethanesulfonic acid has been used as solvent for CV with sodium trifluoromethanesulfonate as supporting electrolyte, glassy carbon as indicator electrode, platinum as counterelectrode and a silver wire as pseudoreference electrode. At v = 100 mV s the accessible potential window was from +0.4 to +3.0 V vs NHE (calibrated against Ru(bpy)3 ) [301]. 

Recently, a mixed sulfonic phosphonic acid was prepared via this route20 (equation 5). Sodium trifluoromethanesulfonate can be prepared in a similar way21 (equation 6). 

Dialkyl phosphonates were converted to tertiary phosphine oxides by reaction with two equivalents of allqrl or aryl Grignard reagents and the same quantity of sodium trifluoromethanesulfonate serving as an activator (Scheme 10). ... 

Rard, J.A., Palmer, D.A., and Albright, J.G. (2003) Isopiestic determination of the osmotic and activity coefficients of aqueous sodium trifluoromethanesulfonate at 298.15 K and 323.15 K, and representation with an extended ion-interaction (Pitzer) model. / Ghent. Eng. Data, 48, 158-166. 

The molal dissociation quotients of water in sodium trifluoromethanesulfonate solutions to high temperatures. J. Solution Chem., 17, 153-164. 

The metallic salts of trifluoromethanesulfonic acid can be prepared by reaction of the acid with the corresponding hydroxide or carbonate or by reaction of sulfonyl fluoride with the corresponding hydroxide. The salts are hydroscopic but can be dehydrated at 100°C under vacuum. The sodium salt has a melting point of 248°C and decomposes at 425°C. The lithium salt of trifluoromethanesulfonic acid [33454-82-9] CF SO Li, commonly called lithium triflate, is used as a battery electrolyte in primary lithium batteries because solutions of it exhibit high electrical conductivity, and because of the compound s low toxicity and excellent chemical stabiUty. It melts at 423°C and decomposes at 430°C. It is quite soluble in polar organic solvents and water. Table 2 shows the electrical conductivities of lithium triflate in comparison with other lithium electrolytes which are much more toxic (24). 

To a solution of dihydronaphthalene 41 (250 mg, 0.77 mmol) in CH2CI2 (5 mL) was added methyl trifluoromethanesulfonate (227 mg, 1.38 mmol). The mixture was stirred at rt until the starting material had been completely consumed as judged by TLC analysis (3 h). The mixture was cooled to 0°C and a solution of NaBHt (111 mg, 2.92 mmol) in 4 1 MeOH THF (3 mL) was slowly added. The mixture was warmed to rt then quenched with saturated aqueous ammonium chloride (50 mL). The resulting mixture was extracted with CH2CI2 (3 X 50 mL) and the combined organic extracts were dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The resulting material was dissolved in 4 1 THF/H2O (5 mL) and oxalic acid (485 mg, 3.85 mmol) was added. The reaction... 

Dibenz[r,e,]azcpinium salts, e.g. 3 and 6, arc also obtained by O- and 5-alkylation of 6,7-dihydro-5//-dibenz[f,e]azepin-7-ones 2 and -7-thiones 5 with trimethyloxonium tetrafluo-roborate.181 iodomethane,181 or methyl trifluoromethanesulfonate.12 Treatment of the tri-fluoromethanesulfonates 3 and 6 (X = OTf), or the tetrafluoroborate 6 (X = BF4) with 2 M sodium hydroxide in dichloromethane liberates the free bases 4 and 7, respectively.7,181... 

An easy synthesis of the 2-oxo-2,3-dihydro-l/7-pyrrolo[l,2- ]pyrazole system can be performed by reaction of 1,2-diaza-1,3-butadienes 33 with dialkyl 1,3-acetonedicarboxylate 34 in the presence of potassium carbonate. At first, 1-aminopyrroles 36 was produced by dehydration in the presence of copper(n) trifluoromethanesulfonate. Treatment of these compounds with sodium hydride led to ATZ-substituted 2-oxo-2,3-dihydro-17/-pyrrolo[l,2-A]pyrazole 38. Under the same reaction conditions, and after acidic treatment, NH-BOC-protected 1-aminopyrrole was transformed to NH-unsubstituted 2-oxo-2,3-dihydro-l//-pyrrolo[l,2-A]pyrazole 37 (BOC =/-butylcarbonyl) (Scheme 1). 

The synthesis of imidazo[2,Tc][l,2,4]triazolo-3-thiones has been investigated. For instance, the reaction of 1,2,4-triazoline-3-thione 361 <1995JHC275> with methyl trifluoromethanesulfonate affords the stable 3-methylmercapto-1,2,4-triazolium trifluoromethanesulfonate 362 in quantitative yield, which after treatment with sodium bicarbonate and bromine provides 6-bromomethyl-2,6-dimethyl-7-ethoxycarbonyl-2,3,5,6-tetrahydro-7//-imidazo[2,T4-[l,2,4]triazolo-3-thione 10 in 47% yield, via intermediate 363 (Scheme 36) <1996T791>. 

Alkylation or acylation takes place at the nitrogen in position 1 when l/7-[l,2,4]triazolo[4,3-A][l,2,4]triazole 9 is treated with methyl iodide or acetyl chloride, furnishing compound 10 or 11, respectively <1983S415>. The 7-methyl isomers 13 are obtained after conversion of compounds 9 into the 1-acetyl derivatives 11 followed by methylation with methyl trifluoromethanesulfonate to give the l-acetyl-6-aryl-7-methyl-3-methylthio-17/-[l,2,4]triazolo[4,3-A]-[l,2,4]triazol-7-ium-trifluoromethanesulfonates 12, which upon treatment with aqueous sodium carbonate afford the 7-methyl derivatives 13 <1985BCJ735>. 

The reaction was performed in flame-dried modified Schlenk (Kjeldahl shape) flask fitted with a glass stopper or rubber septum under a positive pressure of argon. Trifluoromethanesulfonic anhydride (1.4 equiv) was added to a solution of giycosyl donor (0.191 mmol, 1 equiv) and diphenyl sulfoxide (2.8 equiv) in a mixture of toluene and dichloromethane (8 ml, 3 1 vol/vol) at — 78 °C. The reaction mixture was stirred at this temperature for 5 min and then at —40 °C for 1 h. At this time, 2-chloropyridine (5.0 equiv) and the giycosyl acceptor (3.0 equiv) were added sequentially at —40 °C. The solution was stirred at this temperature for 1 h, then at 0 °C for 30 min and finally at 23 °C for lh before the addition of excess triethylamine (10 equiv). The reaction was diluted with dichloromethane (100 ml) and was washed sequentially with saturated aqueous sodium bicarbonate solution (2 x 100 ml) and saturated aqueous sodium chloride (100 ml). The organic layer was dried (sodium sulfate) and concentrated. The residue was purified by silica gel flash column chromatography. 

The third procedure illustrated by this preparation involves the reaotion of ketones with trifluoromethanesulfonic anhydride in a solvent such as pentane, methylene chloride, or carbon tetrachloride and in the presence of a base such as pyridine, lutidine, or anhydrous sodium carbonate.7-11,15 This procedure, which presumably involves either acid-catalyzed or base-catalyzed enolization of the ketone followed by acylation of the enol with the acid anhydride, has also been used to prepare other vinyl sulfonate esters such as tosylates12 or methanesulfonates.13... 

Beccalli et al. reported a new synthesis of staurosporinone (293) from 3-cyano-3-(lH-indol-3-yl)-2-oxo propionic acid ethyl ester (1464) (790). The reaction of 1464 with ethyl chlorocarbonate and triethylamine afforded the compound 1465, which, on treatment with dimethylamine, led to the corresponding hydroxy derivative 1466. The triflate 1467 was prepared from 1466 by reaction with trifluoromethanesulfonic anhydride (Tf20) in the presence of ethyldiisopropylamine. The palladium(O)-catalyzed cross-coupling of the triflate 1467 with the 3-(tributylstannyl)indole 1468 afforded the vinylindole 1469 in 89% yield. Deprotection of both nitrogen atoms with sodium ethoxide in ethanol to 1470, followed by photocyclization in the presence of iodine as the oxidizing agent provided the indolocarbazole 1471. Finally, reductive cyclization of 1471 with sodium borohydride-cobaltous chloride led to staurosporinone (293) in 40% yield (790) (Scheme 5.248). 

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