The synthesis methods of p-toluenesulfonic acid
Liquid Toluenesulfonic acid 94% has wide application as an organic acid catalyst in resin and organic reactions.
P-Toluenesulfonic Acid Synthesis - YouTube
Tosic acid has also been used to catalyze internal translactonization processes (eq 9).Dehydration of ketols to ,-unsaturated compounds is effectively catalyzed by tosic acid; addition of calcium chloride to the reaction mixture has been noted to give superior results in some instances., Other acid-catalyzed processes can occur concomitantly, such as cleavage of silyl ethers. Tosic acid adsorbed on silica gel was found to be an effective catalyst for the dehydration of secondary and tertiary alcohols (16 examples), including a number of steroid alcohols which are resistant to most methods of catalyzed dehydration (eq 10).
The solubilities of -toluenesulfonic acid monohydrate (PTSA·H2O) and sodium -toluenesulfonate (NaPTS) in aqueous sulfuric acid solutions were investigated at a temperature range from 278.45 to 342.95 K. The experimental results showed that the solubilities of PTSA·H2O and NaPTS in aqueous sulfuric acid solutions increased with temperature from 278.45 to 342.95 K and decreased with sulfuric acid concentrations from 0 to 0.7. The experimental data were correlated with the modified Apelblat equation. The calculated results showed good agreement with the experimental data. A new strategy which sodium sulfate was used as a starting material in the preparation of NaPTS was profiled according to the solubility difference between PTSA·H2O and NaPTS. In the continuous preparation of NaPTS, the favorable mole ratio (PTSA·H2O to sodium sulfate) is chosen as 4.0, and the optimum operation conditions of the recycle process were determined, which improved the present process of 4-methylphenol production.
Synthesis of p-Toluenesulfonic Acid Monohydrate - …
-Toluenesulfonic acid has been used to catalyze the formation of enamines; water is removed via azeotropic distillation. The dehydration of primary nitro compounds by tosic acid provides access to nitrile oxides, which can subsequently engage in 1,3-dipolar cycloaddition reactions. Oximes may be dehydrated to nitriles by heating with tosic acid in DMF. Reaction of cyclohexanone oximes with ketene in the presence of tosic acid results in aromatization to aryl amines. This constitutes a milder method for Semmler-Wolff aromatization than those previously reported.
A similar rearrangement has been utilized in the synthesis of cyclopentanoid sesquiterpenes (eq 12). Similar processes in which the migrating atom is sulfur have been reported; sulfur-containing bicyclo[10.5.0]alkenes and related compounds have been obtained via tosic acid-catalyzed ring expansions of sulfoxides (eq 13).Treatment of tertiary vinyl alcohols with tosic acid in a mixture of and effects their conversion to allylic acetates (eq 14). Treatment of -hydroxyalkyl phenyl sulfides with tosic acid in refluxing benzene results in migration of the phenylthio group to generate allylic sulfides.Tosic acid is, in general, superior to other common catalysts (, , potassium acetate) for enolization in the conversion of ketones to their enol acetates using acetic anhydride., This methodology has been used extensively in steroid synthesis. Isopropenyl acetate may also be used with removal of acetone by slow distillation (eq 15). Enol ethers may similarly be obtained by treatment with tosic acid and alcohol in refluxing benzene or toluene followed by azeotropic removal of water.Tosic acid has been used to good effect in the acetylation of steroid substrates, replacing the commonly used catalyst.
p-Toluenesulfonic acid - Wikipedia
The transition state is the maximum in the middle. On the lhs we have the product, in which H-H is eliminated. On the rhs we have the reactant, which in fact resembles (b) more than (a) (the O…B bond is 1.62Å). Note also the relatively low activation barrier for elimination of H2 (~8.2 kcal/mol). There is another feature, being an inflexion point on the lhs, which reveals a tendency to form a 5-coordinate boron on the way to elimination of hydrogen gas. These types of feature have been noted in .
And to complete things, the below shows an animated for (c). This reveals that the approach of BH3 to the carboxylic acid is in fact synchronous with elimination of H2; there is no prior coordination between B and O.
Treatment of cholestane-3,5,6-triol with pyridine and acetic anhydride afforded the 3,6-diacetate; heating the triol with tosic acid in acetic anhydride provided the desired triacetate. Acetylation of the 17-hydroxyl group of progesterone has been accomplished by this method.,Esters may be prepared by the acid-catalyzed addition of alcohols to nitriles.
p-TOLUENESULFONIC ACID MONOHYDRATE
p-Toluenesulfonic acid CAS#: 104-15-4
p-Toluenesulfonic acid monohydrate is the leading high purity catalyst in organic syntheses of all kinds.
p-toluenesulfonic acid , Hive Chemistry Discourse
Liquid Methanesulfonic acid is a non-aromatic sulfonic acid used in NA organic reactions and metal treatment
A good commercial grade of p-toluenesulfonic acid monohydrate, m.p
Minimum Order Quantity ,more about p-Toluenesulfonic acid Prices, for sale,please click on Contact.
p-Toluenesulfonic acid | Sigma-Aldrich
The example chosen is the reduction of a carboxylic acid to an alcohol by borane (diborane). Lecture notes present this reaction as being specific to carboxylic acids, even in the presence of carboxylic esters. The tutor is then faced with how to explain this selectivity to students in a tutorial, using arrow pushing.
Search results for p-Toluenesulfonic acid at Sigma-Aldrich
Process 3 is the one which involves the essential (red) arrow pushing. It encapsulates the reason why only a carboxylic acid reacts in this process, and these arrows can be formalised by computing the transition state quantum mechanically (below). In fact there are two ways of illustrating this essential process. Process 2 involves first forming a O-B bond before the essential arrows. Process 4 involves another B-O bond AFTER the key transition state; the outcome of either process is identical. This illustrates another subtle behaviour in arrow pushing; the detailed timing or choreography of the arrows. In this example, the animated form of the reaction coordinate indicates relatively little B-O bond formation, so we will go with 2 and then 5 as the more realistic representation. In fact, the QM transition state is fascinating in its own right; note for example how one of the two extruding hydrogen atoms is moving far less (the hydridic one) than the other (the proton-like one; full details available at ).
p-Toluenesulfonic Acid Mediated 1,3-Dipolar …
It is utilized frequently in many of the common acid-catalyzed reactions and transformations in organic chemistry, including esterification, formation of acetals, dehydration processes, preparation of enol ethers and acetates, and rearrangement and isomerization processes.
p-Toluenesulfonic acid | C7H8O3S | ChemSpider
Physical Data: the anhydrous acid exists as monoclinic leaflets or prisms, mp 106–107 °C; pKa −6.62 (H2SO4). There is also a metastable form, mp 38 °C. The monohydrate is a white crystalline powder, mp 103–106 °C.
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