Methane sulfonic acid catalyst

The cyclic dimerization of HIBA proceeded smoothly in the presence of the dehydration catalyst methane sulfonic acid to isolate the cyclic dimer TMG in a 67% 5deld. Another simple and convenient route for the s5mthesis of TMG from lactic acid has been reported [102]. This method involves three steps (1) one-step protection of lactic acid hy cyclic acetalization employing acetone (2) cc-methylation of the obtained 2,2,5-trimethyl-l,3-dioxolan-4-one and [3] one-pot s5mthesis of TMG including the hydrolysis of 2,2,5,5-tetramethyl-l,3-dioxolan-4-one, resulting in moderate 5deld [49-51%] of TMG. 

Some studies and patents related to the etherification reaction between glycerol and isobutene are available in the literature, which report the production of the ethers with various catalysts, such as zeolites [19], ion-exchange resins [20, 21] and some homogeneous catalysts, e.g., p-toluene sulfonic acid [21, 22] and methane sulfonic acid [22], Recent studies, however, have concentrated on the etherification of glycerol with isobutene on ion-exchange resins [8, 23]. 

Esterification Reactions. The use of solid acids provides a practical substitute for homogeneous acid catalysts commonly employed to prepare alkyl esters. The use of homogeneous acid catalysts, such as sulfuric acid, and p-toluene- or methane-sulfonic acids, generally results in sulfur contamination of the final product, which upon combustion yield compounds that are known pollutants. 

Although zwitterions are mainly considered for their novel ion conductive matrix in this chapter, they are being used as not only as solvents and catalysts for organic reactions [42] but also as organogelators [43]. Zwitterions have been screened as solvent/catalysts for several classical acid-promoted organic reactions such as the Fischer esterification, alcohol dehydrodimerization, and the pinacol/ benzopinacole rearrangement. The zwitterion containing an equimolar trifluoro-methane sulfonic acid is liquid at room temperature. Because they can work as solvent/catalysts, as shown in the reactions discussed in this chapter, zwitterionic liquids should open the door to a whole new area of applications. 

A wide range of chemical agents, catalysts and conditions for the glycolysis of unsaturated polyester resins, used in the manufacture of buttons, have been described in a recent patent.34 In addition to different metal acetates, the following compounds have been proposed to be catalytically active in PET glycolysis sodium methylate, sodium ethylate, sodium hydroxide, methane-sulfonic acid, magnesium oxide, barium oxide and calcium oxide. Different applications of the depolymerization products were described, e.g., preparation of fresh unsaturated polyesters by reaction with maleic acid, maleic acid/ phthalic anhydride or maleic anhydride/terephthalic acid or the synthesis of polyurethane resins by reaction with a diisocyanate. 

The oxidation mechanism of methanethiol on activated carbon fibers (ACF) in the presence of H2S and iron catalyst was proposed by Katoh and coworkers [78]. According to them the process is initiated by, which, through chain reactions with an iron catalyst involved, form OH radicals. Those radicals not only extract hydrogen from polysufide, form chain sulfur radicals, which accelerate the H2S oxidation but also oxidize DMDS formed by partial oxidation. As a product, methane sulfonic acid is expected. This mechanism is true only for the complex system with a mixed supply of the sulfur containing gases,... 

In the first step an amine such as meth)4imidazole is alkylated, e.g. with diethyl sulfate. This is followed by a transesterification step where a long chain alcohol and an acidic catalyst such as methane sulfonic acid are added to the intermediate obtained after quatemization. In order to shift the equilibrium of this reaction to the products, ethanol liberated in the transformation must be efficiently removed by applying mild vacuum. Scheme 2.2-2 shows some of the alcohols converted in this manner. 

Novolacs are usually made under acidic conditions. Oxalic, sulfuric, toluene sulfonic, phenyl sulfonic, methane sulfonic, hydrochloric, and phosphoric acids are the most common catalysts, though nearly any moderately strong acid will probably do. Often selection of the acid has significant effects on the resultant polymer structure or performance. Sometimes acids are selected for their volatility, as it may be necessary to distill the acid off in some processes. 

Zolflgol MA, Khazaei A, Moosavi-Zare AR (2010) Ionic liquid 3-methyl-l-sulfonic acid imidazolium chloride as a novel and highly efficient catalyst for the very rapid synthesis of bis(indolyl)methanes under solvent-free conditions. Org Prep Proced Int 42 95-102... 

Beilstein Handbook Reference) AI3-28532 BRN 1446024 CCRIS 2783 EINECS 200-898-6 HSDB 5004 Kyselina methansulfonova Methane-sulfonate Methanesulfonic acid Methanesulphonic acid Methylsulfonic acid MSA NSC 3718. Used as a polymerization catalyst, as a solvent, and in chemical synthesis. Solid mp B 20 bpio = 167 d = 1.4812 soluble in H2O. poorly soluble in organic solvents. Lancaster Synthesis Co. Uallinckrodt Inc. Sigma-Aldrich Fine Chem. 

As mentioned above, the reaction between phenol and methanal occurs as an electrophilic substitution reaction in an acidic medium. Typical catalysts used are oxalic acid [34-36], sulfuric acid [37,38], and 4-methylbenzene sulfonic acid [39-41 ]. The first reaction step is the formation of a hydroxymethylcaibenium ion, according to equation 9. This reactive intermediate possesses strong electrophilic properties and in the presence of strong acids it can react with the phenol in both the para as well as the ortho position. 

One of the driving forces behind recent developments in the synthesis and characterization of new acids is the requirement to replace mineral acids by reagents and catalysts that will lead to reduction in waste, in other words to an improved atom economy. Thus, HCl used in the synthesis of diamino diphenyl methane, an intermediate in polyurethane production, can be replaced by a silico-aluminate catalyst in which the acid sites of the zeolite are accessible through the external surface. Less conventionally, simple aromatic hydrocarbons can be nitrated using 60-70% nitric acid in the presence of the strong Lewis acids, lanthanide-perfluoroalkane sulfonic acid salts, such as the ytterbium(lll) compounds (VI) and... 

It has been reported previously that bls-trlfluoromethane-sulfonyl methane ("dlsulfone ) and its derivatives are good epoxy homo-polymerization catalysts (11,12). Calorimetric studies have shown that l,l,3,3-tetrakl8(trlfluoro methanesulfonyl) propane ("tetra-sulfone") is probably the only effective catalyst for homopolymerization of an aliphatic epoxide, e.g. butene oxide, in a non-polar solvent at room temperature (Figure 2). The other dlsulfone catalyst along with Bronsted acids are poor catalysts. 

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