Sulfur trioxide-chlorosulfonic acid

The usual sulfonating agent is concentrated sulfuric acid, but sulfur trioxide, chlorosulfonic acid, metallic sulfates, and sulfamic acid are also occasionally used. However, because of the nature and properties of sulfuric acid, it is desirable to use it for nucleophilic substitution wherever possible. 

SMOKES AND OTHER SUBSTANCES Zinc Oxide Phosphorus Smokes Sulfur Trioxide-Chlorosulfonic Acid Titanium Tetrachloride Nitrogen Oxides... 

Sulfur trioxide-chlorosulfonic acid (military designation, FS smoke) consists of 50% (weight/ weight) sulfur trioxide (SO3) and 50% (weight/ weight) chlorosulfonic acid [SO2(OH)C1], FS smoke is typically dispersed by spray atomization. The sulfur trioxide evaporates from spray particles, reacts with moisture in the air, and forms sulfur acid, which condenses into droplets that produce a dense... 

Sulfur trioxide-chlorosulfonic acid (Smoke mixture)... 

Hydrogen fluoride Acetic anhydride, 2-aminoethanol, ammonia, arsenic trioxide, chlorosulfonic acid, ethylenediamine, ethyleneimine, fluorine, HgO, oleum, phosphorus trioxide, propylene oxide, sodium, sulfuric acid, vinyl acetate... 

When chlorosulfonic acid is heated it partially decomposes into sulfliryl chloride (SO2CI2), sulfuric acid, sulfur trioxide, pyrosulfuric acid (H2S2O7), hydrogen chloride, pyrosulfuryl chloride (CI2S2O5) and other compounds. At 170 °C, there is an equilibrium between chlorosulfonic acid, sulfuryl chloride and sulfuric acid (Equation 2). Sulfur dioxide and chlorine are not observed when chlorosulfonic acid is heated between 170 and 190 °C, but do appear at higher temperatures or when it is heated in a sealed tube (Equation 3). ... 

The amine-sulfiir trioxide complexes 334 are valuable sulfonating agents for alcohols and polysaccharides they may also be used for the sulfonation of the acid-sensitive heterocycles (furan and pyrrole) to the 2-sulfonic acids 337 and 338 (Equations 106 and 107). With these substrates, strongly acidic sulfonating agents, such as sulfuric and chlorosulfonic acid, cannot be used because they result in polymerization of the heterocycles. 

Furan 84 is a five-membered r-excessive aromatic heterocycle containing one hetero oxygen atom. It is unstable in acids, forming tars, so like pyrrole (Chapter 6, p 182) the substrate cannot be sulfonated by sulfuric or chlorosulfonic acid. However, again like pyrrole, treatment of furan 84 with sulfur trioxide in either dioxan or pyridine yields the 2-sulfonic acid 85 (Equation 23). 

Nitric acid, fuming Organic matter, nonmetals, most metals, ammonia, chlorosulfonic acid, chromium trioxide, cyanides, dichromates, hydrazines, hydrides, HCN, HI, hydrogen sulflde, sulfur dioxide, sulfur halides, sulfuric acid, flammable liquids and gases... 

Pyridine Chlorosulfonic acid, chromium trioxide, formamide, maleic anhydride, nitric acid, oleum, perchromates, silver perchlorate, sulfuric acid... 

Commercially, sulfonation is carried out by the classic method with sulfuric acid. Modem reactors are glass-lined older equipment was made from cast iron or coated with enamel Processes often use chlorosulfonic acid or sulfur trioxide to minimi2e the need of excess sulfuric acid. Improved analytical methods have contributed to the success of process optimi2ation (9—12). 

Sulfation and Sulfonation. a-Olefin reactions involving the introduction of sulfur-containing functional groups have commercial importance. As with many derivatives of olefins, several of these products have appHcations in the area of surfactants (qv) and detergents. Typical sulfur reagents utilized in these processes include sulfuric acid, oleum, chlorosulfonic acid, sulfur trioxide, and sodium bisulfite. 

Reaction with cold nitric acid results primarily ia the formation of 5-nitrosahcyhc acid [96-97-9]. However, reaction with fuming nitric acid results ia decarboxylation as well as the formation of 2,4,6-trinitrophenol [88-89-1] (picric acid). Sulfonation with chlorosulfonic acid at 160°C yields 5-sulfosahcyhc acid [56507-30-3]. At higher temperatures (180°C) and with an excess of chlorosulfonic acid, 3,5-disulfosahcyhc acid forms. Sulfonation with hquid sulfur trioxide ia tetrachloroethylene leads to a nearly quantitative yield of 5-sulfosahcylc acid (1). 

Sulfosahcyhc acid is prepared by heating 10 parts of sahcyhc acid with 50 parts of concentrated sulfuric acid, by chlorosulfonation of sahcyhc acid and subsequent hydrolysis of the acid chloride, or by sulfonation with hquid sulfur trioxide in tetrachloroethylene. It is used as an intermediate in the production of dyestuffs, grease additives, catalysts, and surfactants. It is also useful as a colorimetric reagent for ferric iron and as a reagent for albumin. Table 9 shows the physical properties of sahcyhc acid derivatives. 

A solution of sulfur trioxide [7446-11-9] dissolved in chlorosulfonic acid [7990-94-5] CISO H, has been used as a smoke (U.S. designation FS) but it is not a U.S. standard agent (see Chlorosulfuric acid Sulfuric acid and sulfur trioxide). When FS is atomized in air, the sulfur trioxide evaporates from the small droplets and reacts with atmospheric moisture to form sulfuric acid vapor. This vapor condenses into minute droplets that form a dense white cloud. FS produces its effect almost instantaneously upon mechanical atomization into the atmosphere, except at very low temperatures. At such temperatures, the small amount of moisture normally present in the atmosphere, requires that FS be thermally generated with the addition of steam to be effective. FS can be used as a fill for artillery and mortar shells and bombs and can be effectively dispersed from low performance aircraft spray tanks. FS is both corrosive and toxic in the presence of moisture, which imposes limitations on its storage, handling, and use. 

Chlorosulfonation of benzotrichloride with chlorosulfonic acid (28) or with sulfur trioxide (29) gives y -chlorosulfonyl benzoyl chloride [4052-92-0] in high yield. Nitration with nitronium fluoroborate in sulfolane gives 68% y -nitro-benzotrichloride [709-58-0] along with 13% of the ortho and 19% of the para isomers (30). 

Other direct methods for the sulfonation of the higher fatty acids are by the use of sulfur trioxide vapor or by the use of chlorosulfonic acid. Indirect methods are also available for the preparation of a-sulfo fatty acids and their salts from an a-bromo fatty acid made by the Hell-Volhard-Zelinsky reaction. The bromo compound may be converted directly to the sodium salt of a sulfonic acid through the Strecker reaction or may be converted to the mercaptan and oxidized to the sulfonate. Sulfonation of the lower fatty acids has been studied by Backer and co-workers. ... 

Sulfonation of the aromatic ring of l, 2, 2 -trifluorostyrene below 0 C does not give satisfactory yields with chlorosulfonic acid or a sulfur trioxide-dioxane complex Tar forms on heating In contrast, under similar conditions ipso substitution IS facile at the position of a trialkylsilyl or -stannyl group Thus, 4-trimethyl-silyl-T 2, 2 D-trifluorostyrene affords the corresponding trimethylsilyl sulfonate [20] (equation 9)... 

Si, and stannic tetrachloride. An effective smoke agent, whether it be mechanically dispersed from an aircraft spray tank or vaporized thermally, is a mixt of S trioxide and chlorosulfonic acid (FS smoke agent) which upon hydrolysis forms sulfuric and hydrochloric acid dispersions. Of course, all such formulations are highly corrosive, and, if not outright toxic, then conducive to pulmonary edema... 

Using sulfur trioxide a nucleophilic aliphatic carbon and an aromatic nucleus may be connected by a sulfonyl bridge479 (equation 93). Instead of sulfur trioxide, sulfuric acid or chlorosulfonic acid is utilized mostly. The procedures differ mainly by the manner in which the water is eliminated480 e.g., a mixture of sulfuric acid and trifluoroacetic anhydride was used recently481. Similarly to equation 93,3-oxo-2,3-dihydrobenzothiophene 1,1-dioxide is available from acetophenone and chlorosulfonic acid482 (equation 94). 

Although widely used in the past and still used in special cases, the industrial sulfation with chlorosulfonic acid presents several problems which have caused the decline of this technique in favor of the more advantageous sulfation method with sulfur trioxide. These problems consist of evolution of the highly corrosive hydrogen chloride, heat transfer characteristics of the reaction, and the comparatively high level of chloride ion in the sulfated product compared with alcohol and alcohol ether sulfates obtained with sulfur trioxide. 

Nitropropane Nitrosyl fluoride Nitrosyl perchlorate Nitrourea Nitrous acid Nitryl chloride Oxalic acid See under Nitromethane chlorosulfonic acid, oleum Haloalkenes, metals, nonmetals Acetones, amines, diethyl ether, metal salts, organic materials Mercury(II) and silver salts Phosphine, phosphorus trichloride, silver nitrate, semicarbazone Ammonia, sulfur trioxide, tin(IV) bromide and iodide Furfuryl alcohol, silver, mercury, sodium chlorate, sodium chlorite, sodium hypochlorite... 

The unsulfonated random copolymers are reportedly synthesized at 50 °C over a period of 48 h using emulsion polymerization with dodecylamine hydrochloride surfactant in water as the reaction system and potassium persulfate as the initiator. The copolymer is then dissolved in an appropriate solvent such as dichloroethane or chloroform and sulfonated using reagents such as chlorosulfonic acid or a sulfur trioxide complex. It has been reported that this generation of BAM membranes exhibited some su-... 

The most common way to modify aromatic polymers for application as a PEM is to employ electrophilic aromatic sulfonation. Aromatic polymers are easily sulfonated using concentrated sulfuric acid, fuming sulfuric acid, chlorosulfonic acid, or sulfur trioxide (or complexs thereof). Postmodification reactions are usually restricted due to their lack of precise control over the degree and location of functionalization, the possibility of side reactions, or degradation of the polymer backbone. Regardless, this area of PEM synthesis has received much attention and may be the source of emerging products such as sulfonated Victrex poly (ether ether ketone). 

Alcohol sulfates (AS) are usually manufactured by the reaction of a primary alcohol with sulfur trioxide or chlorosulfonic acid followed by neutralization with a base. These are high foam surfactants but they are sensitive to water hardness and higher levels of phosphates are required. This latter requirement has harmed the market for this type of detergent, but they are 2% of production for the major household surfactant market. Sodium lauryl sulfate (R = Cn) is a constituent of shampoos to take advantage of its high-foaming properties. 

HCl forms adducts with anhydrous sulfates of several metals, such as ZnS04 "21101. HCl combines with sulfur trioxide to produce chlorosulfonic acid ... 

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