Methyl -Toluenesulfonate

Higher perfluoroalkanesulfonates are slightly more reactive than triflates toward nucleophilic displacements. The rate constants for acetolysis of methyl nonafluorobutanesulfonate [6401 -03-2J, methyl trifluoromethanesulfonate [333-27-7] and methyl toluenesulfonate [80-48-8] are 1.49 x, ... 

All lation. In alkylation, the dialkyl sulfates react much faster than do the alkyl haHdes, because the monoalkyl sulfate anion (ROSO ) is more effective as a leaving group than a haHde ion. The high rate is most apparent with small primary alkyl groups, eg, methyl and ethyl. Some leaving groups, such as the fluorinated sulfonate anion, eg, the triflate anion, CF SO, react even faster in ester form (4). Against phenoxide anion, the reaction rate is methyl triflate [333-27-7] dimethyl sulfate methyl toluenesulfonate [23373-38-8] (5). Dialkyl sulfates, as compared to alkyl chlorides, lack chloride ions in their products chloride corrodes and requires the use of a gas instead of a Hquid. The lower sulfates are much less expensive than lower bromides or iodides, and they also alkylate quickly. 

By heating methyl -toluenesulfonate with sodium nitrite. Rodionow, Alexeieff and Carcarras, Bull. Soc. Chim. (4) 39, 324 (1926). 

Methyl />-toluenesulfonate may be prepared in a somewhat similar manner with good yields. One kilo of methyl alcohol (90-95 per cent) is placed in a round-bottom flask, placed in an ice-salt bath. One kilo of powdered pure -toluenesulfo-chloride (crude material may be used but the yield of product drops to about 75 per cent) is added with mechanical stirring. From a separatory funnel 840 g. of 25 per cent sodium hydroxide solution is added drop by drop. The temperature must be held at about 23-270 for the best results. When all this alkaline solution is added the reaction mixture is tested with litmus if not alkaline, more alkali is added until the neutral point is reached. Upon standing several hours the ester sinks and the alcohol forms the top layer. The alcohol may be siphoned off and used in subsequent experiments, the methyl / -toluene-sulfonate is washed with water to remove a little salt and then with 5 per cent hydrochloric add to dissolve the iron. Finally it is... 

Reaction of rra r-(3-methyl-l-toluenesulfonylaziridin-2-yl)methyl toluenesulfonate 278 with benzyltriethylammonium tetrathiomolybdate gave /ra r-2-(Ar-toluenesulfonylaminomethyl)-3-methylthiirane 279 as a major product and 3-methyl-4-(toluenesulfonylamino)-l,2-dithiolane 280 as a minor product, with excellent regio- and stereocontrol (Equation 42) <2005JA12760>. A tentative mechanism for the formation of thiirane 279 and 1,2-dithiolane 280 is shown in Scheme 80. 

Methyl iodide has been prepared by the action of methyl sulfate on an aqueous solution of potassium iodid by the slow distillation of a mixture of methanol with a large excess of constant-boiling hydriodic acid by the electrolysis of an aqueous solution of potassium acetate in the presence of iodine or potassium iodide by the action of an aqueous solution of potassium iodide on methyl- -toluenesulfonate and by the action of metha-... 

A Methyl-/7-toluenesulfonamide 855 p-Toluenesulfonamide (19 g, 0.11 mole) is added to a hot saturated solution of anhydrous sodium carbonate (21.1g, 0.2 mole)in water (25 ml), and the mixture is boiled under reflux until all is dissolved. Then methyl / -toluenesulfonate (18.6 g, 0.1 mole) is added, and boiling is continued with stirring for a further 2 h. The solution is then allowed to cool, treated with water, and filtered. On acidification of the filtrate some unchanged sulfonamide (1.4 g) is recovered (7.3% of the batch). The original precipitate (crude monomethylamide) is purified by boiling it with an excess of sodium hydroxide solution, filtering off the insoluble dimethylamide (2g, 10% m.p. 86.5°), and recovery by acidification with 17% hydrochloric acid. The A-methyl-p-toluenesulfonamide (13 g, 70.3%) thus obtained is nearly pure it has m.p. 77°. 

Methylation of hippeastrine (LXIII) with potassium and methyl -toluenesulfonate afforded nivaline (LXXXVII) (98). The reverse reactions could be accomplished by refluxing nivaline with 17% hydrochloric acid (96). 

H- )-Epibuphanisine (mp 123°-125° [a]j, -1-141° in CHCI3) was isolated in minor amounts from Ammocharis coranica (4). It formed a perchlorate salt (mp 244°-246° decomp. [a]p - -88° in EtOH). Methylation of (-h )-epiorinine (CXXXIX R = H) with potassium and methyl- -toluenesulfonate afforded CXXXIX (R = CH3), identical with the natural (-I- )-epib.uphanisine (4). 

Biochemistry, Kiev, Ukraine) and water-soluble carbodiimide (V-cyclohexyl-V -(2-morpholinoethyl) carbodiimide methyl-/ -toluenesulfonate, CMC, Sigma) were used as received (Alexeeva et al. 2004). Adsorption experiments were carried out by shaking 0.2% aqueous solutions of individual solutes or proteins with CMC and a carbon sample at room temperature for 1 h. The adsorption of proteins was about 0.2 g/g. In these experimental conditions, unreacted CMC is hydrolyzed and washed out of the system (Alexeeva et al. 2004). Analysis of porous structure of SCN was done using nitrogen adsorption-desorption isotherm recorded at 77.4 K (Alexeeva et al. 2004). The H NMR spectra were recorded by means of a high-resolution WP-100 SY (Bruker) NMR spectrometer at the bandwidth of... 

FIGURE 2.70 The infrared spectrum of methyl / -toluenesulfonate (neat liquid, KBr plates). 

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