Sodium p-toluene-sulfonate

The authors used for the first time aromatic hydrotope solution system such as 50% sodium p-toluene sulfonate aqueous solution (NaPTSA), 40% sodium cumene sulfonate aqueous solution (NaCuS), and 20% sodium p-xy-lene sulfonate (NaXS) aqueous solution to perform Hantzsch ester synthesis. 

A mixture of 3-methylphenylacetonitrile and dry ethanol was cooled in an ice-bath and dry hydrogen chloride was passed. The mixture was allowed to stand at room temperature for 3 days and then treated portionwise, with vigorous shaking and occasional cooling, with a saturated solution of ammonia in dry ethanol. Addition was continued until a smell of ammonia persisted. The mixture was allowed to stand at room temperature for 2 days and then filtered. The fitltrate was treated with a saturated aqueous solution of 1.1 equivalents of sodium p-toluene-sulfonate and diluted with water. The crystalline precipitate was removed and 3-methylphenylacetamidine p-toluenesulphonate (recrystallised from ethanol) was obtained. 

The above dimethylene-L-iditol was shown to be the 2,3 4,5-, 2,4 3,5-or 2,5 3,4-compound by the fact that its ditosyl ester reacted with sodium iodide in acetonylacetone at 110° to give two moles of sodium p-toluene-sulfonate together with a l,6-diiodo-l,6-didesoxy-dimethylene-L-iditol, and by the resistance of the methylene groups to acetolysis.68,110 That the true structure was in fact the second (XXII) of these possibilities was... 

Fig. 10. Effect of inhibiting salts upon the hydrolysis of 2,6-dinitrophenyl phosphate in 3 X lO- MCTABat 25-0° and pH 9 0 A, sodium chloride .sodium methane sulfonate I. sodium P toluene sulfonate O. sodium benzoate . dipotassium phthalate o. disodium terephthalate disodium phenyl phosphate (Bunton et al., 1968).

Figure 18.3. Solubility of the dye fluorescein diacetate (FDA) in aqueous hydrotropic solutions as a function of the hydrotrope concentration at room temperature. Three different hydrotropes, i.e. sodium p-toluene sulfonate (NaPTS), sodium salicylate (NaS) and sodium butyl monoglycol sulfate (NaBMGS) were studied. (Reprinted with permission from Balasubramanian, D. et al., J. Phys. Chem., 93, 3865-3870 (1989). Copyright 2000 American Chemical Society)...

Hydrotropes have been proven to be surface-active. The surface tensions for anionic hydrotropes such as sodium salicylate, sodium xylene sulfonate, sodium p-toluene sulfonate, sodium cumene sulfonate and sodium butyl monoglycol sulfate decrease as a function of the concentration in water, until a plateau is reached (17) (see Figure 18.5). The same behaviour is also observed for the nonionic hydrotropes resorcinol, catechol, and pyrogallol (18). This means that they exhibit the same behaviour as surfactants, even though the drop in surface tension is not as dramatic but more gradual for hydrotropes when compared to surfactants. The concentration for the onset of self-aggregation of the anionic hydrotropes in non-covalent assemblies determined from... 

The solid-liquid alkaline hydrolysis of esters such as phenyl benzoate, ethyl p-nitrobenzoate and 2,4-dichlorophenylbenzoate has been studied in the presence of sodium p-toluene sulfonate, sodium xylene sulfonate and the sodium salts of phenol, p-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol. The solubilities of the esters in water is very low, but in the presence of the hydrotropes considerably higher reaction rates are obtained due to higher solubilities (30). The same behaviour was observed by using urea in the solid-liquid oximation of cyclododecanone where the reaction rate was increased. From studies of these types of reactions, the following observations were made (31) ... 

Sodium vinyl sulfonate Sodium p-toluene sulfonate (ptsa) Sodium p-styrene sulfonate (SSS)... 

Sodium p-toluene sulfon-chloride (chloramine-T) 0.05% aq. Antiseptic Lombardi et al. 1989... 

In a 250 ml Erlenmeyer flask covered with aluminum foil, 14.3 g (0.0381 mole) of 17a-acetoxy-3j5-hydroxypregn-5-en-20-one is mixed with 50 ml of tetra-hydrofuran, 7 ml ca. 0.076 mole) of dihydropyran, and 0.15 g of p-toluene-sulfonic acid monohydrate. The mixture is warmed to 40 + 5° where upon the steroid dissolves rapidly. The mixture is kept for 45 min and 1 ml of tetra-methylguanidine is added to neutralize the catalyst. Water (100 ml) is added and the organic solvent is removed using a rotary vacuum evaporator. The solid is taken up in ether, the solution is washed with water and saturated salt solution, dried over sodium sulfate, and then treated with Darco and filtered. Removal of the solvent followed by drying at 0.2 mm for 1 hr affords 18.4 g (theory is 17.5 g) of solid having an odor of dihydropyran. The infrared spectrum contains no hydroxyl bands and the crude material is not further purified. This compound has not been described in the literature. 

Besides acylation and alkylation reactions, typical carbonyl reactions, such as reduction and substitution, are known. Thus, the oxo group in position 3 of 8 is attacked by sodium cyanide, resulting in the cyanohydrin in 55% yield. Subsequent dehydration with p-toluene-sulfonic acid and acetylation in position 5 gives 1-benzothiepin 12.90... 

To a solution of D-glucose (5.4 g, 30 mmol) in DMF (100 mL, dried over Drierite) kept below 5°C in an ice bath was added 2-methoxypropene (5.2 g, 60 mmol) and p-toluene-sulfonic acid (-10 mg). The mixture was stirred magnetically at 0-5°C until TLC monitoring indicated that all starting material had disappeared (about 5-6 h), whereupon sodium... 

A mixture of 11.8 g of (+/-)-3a,6,7,7a-tetrahydro-4-methyl-2-oxo-ip-indaheptanoic acid methyl ester, 27 ml of ethylene glycol and 300 mg of p-toluene sulfonic acid mono-hydrate in 600 ml of benzene was refluxed with stirring for 18 hours using a Dean-Stark trap to separate the water formed in the reaction. The reaction mixture was cooled and added to 300 ml of cold 5% potassium bicarbonate. The aqueous layer extracted twice with 2 1 benzene-hexene. The combined organic fractions were washed 3 times with saturated aqueous NaCI, dried over sodium sulfate and evaporated to dryness... 

A solution of 4.9 g (12.8 mmol) of methyl-l-(p-nitrobenzoyl)-5-methoxy-2-methyl-3-indolylacetate in 40 ml of acetic acid containing 400 mg of p-toluene-sulfonic acid is refluxed for 20 hours and then concentrated in vacuum. The gummy residue is extracted with ethyl acetate. The extract is filtered from insoluble material, washed with water and dried over sodium sulfate. Removal of the solvent under reduced pressure affords the desired product as yellow crystals MP 185-186°C. 

Next step of this synthesis consisted in the conversion of alcohol (17) to pisiferic acid (1) and this has been described in Fig. (3). The alcohol (17) in hexane was treated with Pb(OAc)4 in presence of iodine at room temperature to obtain the epoxy triene (19) (51%) whose structure was confirmed by spectroscopy. Treatment of (19) with acetyl p-toluene-sulfonic in dichloromethane yielded an olefinic acetate (20) and this was hydrogenated to obtain (21). The compound (22) could be isolated from (21) on subjection to reduction, oxidation and esterification respectively. The conversion of (22) to (23) was accomplished in three steps (reduction with sodium borohydride, immediate dehydration in dichloromethane and catalytic hydrogenation). Demethylation of (23) with anhydrous aluminium bromide and ethanethiol at room temperature produced pisiferic acid (1). Similar treatment of (23) with aluminium chloride and ethanethiol in dichloromethane yielded methylpisiferate (3). 

A number of analogous sulfides (XXXI) were prepared when p-toluene sulfonate esters of methyl reserpate were treated with sodium salts of thiophenols or of methyl mercaptan. It can be assumed that, in this reaction, inversion takes place at position 18 as well. Some of the sulfides thus obtained show some antihypertensive activity when given intravenously to dogs, but they are not active orally. No sedative effects were observed with these compounds. 

Monoalkylation of malonic ester proceeds much more readily than alkylation of simple esters. The enolate is formed from diethyl malonate and alcoholic sodium ethoxide solution. Alkylation is effected in good yield by the use of primary bromides, diethyl sulfate, or ethyl p-toluene-sulfonate. In addition to the simpler primary alkylmalonates listed in Table 51, many higher members have been prepared. The list includes substituted malonates made from diethyl malonate and the following... 

Attempted Synthesis of Specific Hexenyl Acetate Isomers. From Hexanal. Hexanal (5 ml. of 40% technical material) and 25 ml. 2-propenyl acetate were mixed, and 750 mg. p-toluene sulfonic acid was added. This solution was heated at reflux for 12 hours. The solution was then poured into 100 ml. water and extracted with two 50-ml. portions of ether. The combined ether extracts were washed with water, dilute aqueous sodium bicarbonate, and water and dried over sodium sulfate. After evaporating the ether, a gas chromatogram showed two major components present in a 3 2 ratio (probably the trans- and cis-hex-l-en-l-ol acetates, respectively). These components had identical retention times in the gas chromatograms to two of the major components present in the hexene-1 vinylation reactions. 

The synthesis of this type of compound was achieved by nucleophilic attack of the nitrogen of the C-3 hydrazone residue on C-6 of 65c when it carries a leaving substituent such as a sulfonyloxy group or a bromine atom. This intramolecular heterocyclization process was achieved by the action of sodium iodide in acetone or by the action of acetic anhydride on the mono-O-p-toluene sulfonate to give 111 and 114, respectively (82MI5) (Scheme 28). The spectral data confirmed the assigned structure. 

The primary site of electrophilic attack on 5(4//)-oxazolones is at position C-4. The oxazolones are activated by deprotonation. For example, a variety of 2,4-disubstituted-5(4.H)-oxazolones (80) react with l-fluoro-2,4-dinitrobenzene and sodium carbonate to give 2,4,4-trisubstituted products <88CB67>. When the products are refluxed in methanol containing a catalytic amount of p-toluene-sulfonic acid, they rearrange to 1-hydroxyindazoles (81) (Scheme 24). Apparently, under certain conditions the site of electrophilic attack may be diverted to the 2 position <93TL3907>. Methylene chloride solutions of a, -unsaturated aldehydes, ketones, and esters containing a catalytic amount... 

The unsubstituted l,3-dithiole-2-thione (245) can be accessed, however, by the reaction of dimethyl acetylenedicarboxylate with l,3-dithiolane-2-thione (Scheme 50) <74JOC2456>, from the reaction of sodium acetylide with carbon disulfide and elemental sulfur <64CB1298>, or by a two-step synthesis from the 1,2-dichloroethyl ethylether (246) and potassium trithiocarbonate. The intermediary 4-ethoxy-l,3-dithiolone-2-thione (247) affords, upon reaction with p-toluene sulfonic acid with concomitant loss of ethanol, the unsubstituted derivative (245) <76CC920>. 

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