Alkanesulfonic acids

Whereas superaeid (HF/BF3, HF/SbF, HF/TaF FS03FI/SbF3, etc.)-eatalyzed hydroearbon transformations were first explored in the liquid phase, subsequently, solid aeid eatalyst systems, sueh as those based on Nafion-H, longer-chain perfluorinated alkanesulfonic acids, fluorinated graphite intercalates, etc. were also developed and utilized for heterogeneous reactions. The strong acidic nature of zeolite catalysts was also successfully explored in cases such as FI-ZSM-5 at high temperatures. 

Sulfonate Esters. These are marketed as efficient and easily processible plasticizers with good resistance to extraction. They are typically aryl esters of a to alkanesulfonic acid. 

Fluorinated and Ghlorfluorinated Sulfonic Acids. The synthesis of chlorinated and fluorinated sulfonic acids has been extensively reviewed (91,92). The Hterature discusses the reaction of dialkyl sulfides and disulfides, sulfoxides and sulfones, alkanesulfonyl haHdes, alkanesulfonic acids and alkanethiols with oxygen, hydrogen chloride, hydrogen fluoride, and oxygen—chloride—hydrogen fluoride mixtures over metal haHde catalysts, such as... 

Tetrabutylammonium iodide in trifluoroacetic anhydride is an effective reducing reagent [dS] This system can be used for direct reduction of arenesulfonic acids to the corresponding thiols or disulfides m moderate yields under mild conditions (equation 18) Alkanesulfonic acids are reduced by this system to disulfides with 30-57% yields [dfi]... 

The extract consists of alkanesulfonic acid, sulfuric acid, paraffin, water, and dissolved sulfur dioxide. After degassing to remove the sulfur dioxide (3), the extract has approximately the composition given in Table 2. 

In a falling film evaporator (4) a water-paraffin mixture is distilled off and completely pumped back to the reactor. The resulting product is separated into a 60% sulfuric acid fraction and paraffin-containing alkanesulfonic acid (5), which is bleached by hydrogen peroxide (6). In a stirred vessel (7) the alkanesulfonic acid is neutralized by 50% sodium hydroxide solution until the pH is exactly 7. The composition of the neutralized product is also given in Table 2. 

FIG. 3 Sulfoxidation with solvent extraction of alkanesulfonic acids (Hiils process). 

Unavoidable traces of oxygen in the raw material (e.g., up to 70 mg 02/L alkane at 20°C) and of water in the ppm range produce between 0.1% and 0.5% free alkanesulfonic acid and some sulfuric acid in the product. 

Analysis of sulfonic acid species in sulfonated olefins. Kupfer and Kuenzler [108] reported the determination of acid species following partition between a 6.5% hydrochloric acid solution in 40% ethanol and a 1 1 (v/v) propan-2-ol-hexane mixture. The organic fraction contains alkenesulfonic and hydroxy-alkanesulfonic acids and the aqueous phase disulfonic acids and sulfato-sulfonates. The monosulfonic acids were converted to methyl esters and separated by column chromatography. To determine sulfatosulfonates the aqueous fraction was hydrolyzed and then partitioned and chromatographed. The separation is controlled using IR spectroscopy. 

Oxidation of alkanethiols to alkanesulfonic acids with excess cone, acid as usually described is potentially hazardous, the exotherm often causing ignition of the thiol. A modified method involving oxidation under nitrogen and at temperatures 1-2 C above the m.p. of the thiol is safer and gives purer products [1]. Technical butanethiol (containing 28% of propane- and 7% of pentane-thiols) is hypergolic with 96% acid [2], Oxidation of several thiols to the sulfonic acids by addition to stirred cone, acid had been effected normally, but when 2 new... 

Alkanesulfonic acid Cetylpyridium Tris(2,2 -dipyridyl)ruthenium(ii)mono dicarboxylic acids ODS silica 60% aq. MeOH 17... 

The acid catalysts include sulfuric acid, phosphoric acid, hydrogen fluoride, dihydroxyfluorboric acid, and alkanesulfonic acids. Some heavy metal sulfates, phosphates, sulfides and other salts are also catalysts it seems probable that they undergo partial reduction to acidic compounds during the polymerization reactions. 

MSA and other lower alkanesulfonic acids are useful for plating of lead, nickel, cadmium, silver, and zinc (409). MSA also finds use in plating of tin, copper, lead, and other metals. It is also used in printed circuit board manufacture. In metal finishing the metal coating can be stripped chemically or electrolytically with MSA. MSA also finds use in polymers and as a polymer solvent and as a catalyst for polymerization of monomers such as acrylonitrile. MSA also finds use in ion-exchange resin regeneration because of the high solubility of many metal salts in aqueous solutions. 

Frequently substantially more than catalytic amounts of a Lewis acid metal halide are required to effect Friedel-Crafts alkylation. This is due partly to complex formation between the metal halide and the reagents or products, especially if they contain oxygen or other donor atoms. Another reason is the formation of red oils. Red oils consist of protonated (alkylated) aromatics (i.e., arenium ions) containing metal halides in the counterions or complexed with olefin oligomers. This considerable drawback, however, can be eliminated when using solid acids such as clays,97 98 zeolites (H-ZSM-5),99,100 acidic cation-exchange resins, and perfluoro-alkanesulfonic acid resins (Nafion-H).101-104... 

Efficient catalytic alkane nitrations can be performed with the assistance of N-hydroxyphthalimide (NHPI) with N02 in air [Eq. (10.57)]298 or with HNO3.299 NHPI may also be used to form alkanesulfonic acids by reacting alkanes with S02 300... 

The first catalytic sulfoxidation of saturated hydrocarbons with S02/02 by vanadium catalysts to give alkanesulfonic acids has been reported.302 The best results were achieved with VO(acac)2 ... 

Esterification of sulfonic acids.1 Sulfonic acids are converted into methyl or ethyl esters on reaction with trimethyl or triethyl orthoformate. Yields are >80% in esterification of arenesulfonic acids, but are somewhat lower in the reaction of alkanesulfonic acids because of volatility of the products. 

Jones and co-workers976 have recently reported the use of catalyst 49 (Figure 5.15) with perfluorinated alkanesulfonic acid sites anchored to SBA-15 as a methylaluminoxane-free supported cocatalyst for ethylene polymerization. When catalyst 49 and trimethylaluminum were used in combination with Cp 2ZrMe2 as the metallocene precatalyst, productivities as high as 1000 kg polyethylene molZr-1 h 1 were obtained without experiencing reactor fouling. 

Alkanethiols. Oxidation of alkanethiols to alkanesulfonic acids with concentrated HNO3 may cause ignition of the thiol.15... 

Cationic polymerization of epoxides by irradiation of charge-transfer complexes has been mentioned in the literature Fluorinated alkanesulfonic acid salts chromates and dichromates of alkali metals, alkaline earth metals and ammonium phototropic o-nitrobenzyl esters iodocyclohexene unsaturated nitrosamines and carbamates have been reported to act as cationic photoinitiators. 

Cooper et al. (1992, 1997) identified a homologous series of C1-C4 alkyl phosphonic acids and alkanesulfonic acids in water extracts from Murchison. Isomeric diversity was apparent with five of the eight possible C1-C4 alkyl phosphonic and seven of the eight C1-C4 alkanesulfonic acids identified. The relative abundances of both classes of compound decreased exponentially with increasing carbon number. 

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