Ammonium p-toluenesulfonate

Ion-pair chromatography has also been used for the separation of aspartame from other sweeteners. The ion-pair reagents commonly used are triethylammonium phosphate (32), tetra-ethylammonium hydroxyde (47), tetrapropylammonium hydroxide (40), pentanesulfonate (52), tetrabutylammonium phosphate (34), tetrabutylammonium hydrogen sulfate (66), and tetrabutyl-ammonium p-toluenesulfonate (24). 

Under nominally aprotic conditions, 1,2-protonation dominates in naphthalene. Reduction of naphthalene in anhydrous acetonitrile containing tetraethyl ammonium p-toluenesulfonate yields 1,2-dihydronaphthalene, which is subsequently reduced to tetralin [169]. Similarly, reduction of I in anhydrous DMF gives 1,3,5-cyclooctatriene almost exclusively [53]. The formation of the thermodynamically more stable products is most probably due to base-catalyzed isomerization. 

Fatty acid diethanolamides, N,N-bis(2-hydroxyethyl)-N-4-octyl-N-methyl-ammonium-p-toluenesulfonate... 

Catalysts. Catalyst addition was weight percent on polymer solids. Solution polymers employed, for example, 2-hydroxycyclohexane-p-toluene sulfonate or Nacure 155 (King Industries, dlalkylnaphthalene disulfonic acid) as organic soluble acids. A variety of catalysts were tested with emulsion polymers, the best choice varied with base polymer hydrophobicity and functional monomer distribution. Some of these Included p-toluenesulfonic acid (PTSA), ammonium chloride,... 

Carboxylic acids, ammonium salts Catechins p-Toluenesulfonic acid (20% in Fluorescent spots under long-wave 50... 

Methyl chlorocarbonate Formic acid, chloro-, methyl ester (8) Carbonochloridlc acid, methyl ester (9) (79-22-1) letraethylammonlum p-toluenesulfonate Ammonium, tetraethyl-, p-toluenesulfonate (8) Ethanammium, N,N,N-triethyl-, salt with 4-methylbenzenesulfonic acid (1 1) (9) (733-44-8)... 

The principle has been known since the 1940s, but it was M.M. Baizer who initiated in 1959 the use of quaternary ammonium salts such as tetraethylammo-nium p-toluenesulfonate in this reaction, leading to mass yields of 90% ADN. Together with Monsanto he commercialized and improved the process ever since. First used process setups consisted of divided cell reactors with catholytes of an aqueous solution... 

The simultaneous protection of the 3 and S hydroxy groups of nucleosides and the 4,6- or 3,4-hydroxyls of hexopyranoses is a common problem in organic synthesis. In the case of hexopyranoses, we have already seen that benzylidene acetals and, in certain circumstances, isopropyiidene acetals can be used to good effect. An alternative silicon-based group would offer a wider repertoire of conditions for mild deprotection and such a group was devised by Markiewicz the 1,1,3,3-tetraisopropyldisiloxanylidene group (abbreviated TIPDS),22 229 TIPDS groups are stable to water, 0.3 M p-toluenesulfonic acid in dioxane, 10% tri-fluo mace tic acid in chloroform, 5 M ammonium hydroxide in dioxane-H20 (4 1), and tertiary amines in pyridine,... 

Golding J, Forsyth S, MacFarlane D R, et al. MethanesuRonate and p-toluenesulfonate salts of the N-methyl-N-alkylpyrrohdinium and quaternary ammonium cations Novel low cost ionic liquids. Green Chem. 

Acetylation Acetic anhydride. N-Acetoxyphthalimide. 2- and 3-Acetoxypyridine. Acetyl chloride. N-Acetylimidazole. Boron trifluoride. Catalysts (see Acetic anhydride). Ketene. Magnesium. Methyl oxocarbonium hexafluoroantimonate. Perchloric acid. Phenyl acetate. Pyridine. Sodium acetate. Tetraelhylammonium acetate. p-Toluenesulfonic acid. Tri-n-hexylethyl ammonium hydroxide. 2,4,6-Triisopropylbenzenesulfonyl chloride. Trityl-sodium. Zinc chloride. 

Selective oxidation of methyl groups can be achieved by platinum salts in aqueous solution. Thus, p-toluenesulfonic acid is oxidized to the alcohol and then to the aldehyde by the Pt(II)/Pt(IV) system. Likewise the methyl group of ethanol can be oxidized without affecting the hydroxyl group [208]. Potassium or sodium bromate in the presence of cerium ammonium nitrate in a water/di-oxane (2 3) mixture can oxidize toluene into a 1 1 mixture of benzaldehyde and benzoic acid. Ethylbenzenes yielded acetophenones [209]. 

The key to this process [63, 64] was the addition of a quaternary ammonium salt (tetraethy-lammonium p-toluenesulfonate or tetraethylammonium ethylsulphate) to the reaction medium, which increased the solubility of acrylonitrile in the aqueous electrolyte and generated an aprotic organic layer on the cathode surface that inhibited the synthesis of propionitrile by-products (formed by the simple reduction of acrylonitrile). 

In the third approach, shown in Scheme 7.3.8, a glucose derivative was converted to an epoxide via hydrolysis of the acetonide followed by tosylation of the terminal hydroxyl group and treatment with sodium hydride. Subsequent removal of the PMB group with ceric ammonium nitrate and treatment with p-toluenesulfonic acid effected cyclization to the pyranoside. 

Alkylation of dimedone with phenacyl bromide in the presence of potassium carbonate afforded triketone 62, which upon further alkylation at the same site with Mel in the presence of DBU gave 63. Subsequent treatment of 63 with liquid ammonia afforded hydroxypyr-roline 64 whose dehydration with p-toluenesulfonic acid in boiling benzene, hot acetic acid, dry HC1 in EtOH and 4A molecular sieves or Florisil in benzene afforded indolizine 65 rather than the expected 66. Alternatively, 65 was obtained upon heating 64 to its melting point or by treatment of 63 with ammonium acetate in boiling acetic acid. Different mechanisms were proposed for this rearrangement (88JCS(P1)161) (Scheme 11). 

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