Chlorosulfonic acid, reactions with

EXPLOSION and FIRE CONCERNS flammable liquid when exposed to heat, flame, or oxidants NFPA rating Health 2, Flammability 2, Reactivity 0 dangerous explosion hazard reacts vigorously with oleum and chlorosulfonic acid reaction with water or steam produces toxic and corrosive fumes formation of peroxides may occur in containers that have been opened and remain in storage incompatible with strong oxidizers decomposes in the presence of moisture to form hydrochloric acid use dry ehemical, foam, carbon dioxide, or water spray for firefighting purposes. 

Chlorosulfonic acid, particularly with batch operation, is best suited for production of a range of products on a relatively small scale. Chlorosulfonic acid is still used for the sulfonation of fatty alcohols, fatty alcohol/ethoxylates, and related detergent raw materials with OH groups available for the attachment of an S03H group. For example, the reaction of lauryl alcohol with chlorosulfonic acid illustrates for example the chemistry involved ... 

Chlorosulfonic acid added with stirring at 20° to a soln. of chloral hydrate in CC14, benzonitrile added after 10 min., followed by more chlorosulfonic acid, the exothermic reaction checked by external cooling, and worked up after 1 hr. —> N,N -dibenzoyl-l,l-diamino-2,2,2-trichloroethane. Y 85%. (L. Haskelberg and D. Lavie, J. Org. Chem. 14, 498 (1949).)... 

ACETATO de ETILO (Spanish) (141-78-6) Forms explosive mixture with air (flash point 135°F/57°C oc). Violent reaction with oxidizers, chlorosulfonic acid. Incompatible with strong acids, nitrates, lithium aluminum hydride, lithium tetrahydroaluminate, oleum. Will hydrolyze on standing, forming acetic acid and ethyl alcohol this reaction is greatly accelerated by strong bases. 

ACETIC ETHER (141-78-6) Forms explosive mixture with air (flash point 135°F/57°C oc). Violent reaction with oxidizers, chlorosulfonic acid. Incompatible with strong acids, nitrates. 

A monosulfate is formed when sulfuric [reaction (25)] or chlorosulfonic acid [reaction (26)] reacts with an alcohol ... 

Swaminathan and co-workers discovered an unprecedented Lewis acid-mediated cyclization of the amide acetal 536 to afford 37 in excellent yield (Scheme 1.147). The crude oxazoline 537 is not isolated but immediately treated with Na0CH3/CH30H to produce 37 in excellent yield and purity. The initial reaction conditions used an expensive Lewis acid TMSOTf together with the teratogenic solvent 1,2-dimethoxyethane. These were subsequently replaced with the inexpensive acid chlorosulfonic acid and with methyl acetate as the solvent. Ultimately, this process was refined to a one-pot procedure that afforded 37 in 81% overall yield. The amide acetal 540 was readily prepared in 45% overall yield from methyl 3-methoxyacrylate. 

Less mechanistic studies have been carried out with chlorosulfonic acid than with sulfuric acid and generally the precise nature of the electrophilic species involved remains uncertain and appears to vary with the nature of the substrate and the reaction conditions. Experimental data and thermodynmnic studies indicated that when an aromatic substrate reacts wifii an equimolar quantity of chlorosulfonic acid, the first step )delds the sulfonic acid (Equation 21). In the presence of an excess of the reagent, the initially formed sulfonic acid is slowly converted into the sulfonyl chloride with liberation of sulfuric acid (Equation 22). 

Studies of the reaction of benzene with chlorosulfonic acid (one molar equivalent) showed that the major product was benzenesulfonic acid (Equation 21) with a little diphenyl sulfone. When an excess of chlorosulfonic acid was used benzenesulfonyl chloride was obtained (Equation 22). Spryskov and Kuz mina demonstrated the reversibility of Equation 22 and measured the equilibrium constants for several different aromatic substrates. In the benzene-chlorosulfonic acid reaction, the quantity of diphenyl sulfone produced was increased by addition of anhydrous benzenesulfonic acid, but not by benzenesulfonyl chloride. The sulfone therefore apparently derived from reaction of benzenesulfonic acid and benzene under the influence of chlorosulfonic acid. Sulfone formation appeared to be relatively favoured at low temperatures and this may be due to the formation of an intermediate pyrosulfuric acid (Equations 23,24). 

Several diaryl azines have been successfully chlorosulfonated by reaction with a large excess of chlorosulfonic acid under forcing conditions. For instance, benzaldehyde azine 435 reacted with the reagent (12 equivalents) at 120 C (4 hours) to give the 3,3 -disulfonyl chloride 436, 39% (Equation 134). ... 

Monobenzo- and dibenzocrown ethers are chlorosulfonated by reaction with a large excess of chlorosulfonic acid. Monobenzo-12-crown-4, -15-crown-5 and -18-crown-6-ethers, when treated dropwise with chlorosulfonic acid (10 equivalents) in chloroform solution at —10 to —5 C and the reaction mixture left at RT (five to six hours), gave the corresponding sulfonyl chlorides in 65-75% yield. For instance, monobenzo-12-crown-4-ether 498 afforded the chlorosulfonyl derivative 499. The orientation of sulfonation is, as expected, p to the electron-donating oxygen atom. 

Carbohydrates can be sulfated by treatment with chlorosulfonic acid, but with such polyhydroxy compounds, the reaction often yields a complex mixture of sulfates. However, in some cases, the use of an equimolar quantity of the reagent in chloroform or pyridine solution at low temperature may result in monosulfation, since the primary hydroxyl groups are more readily sulfated. This is generally more effectively achieved by the use of a suitably blocked carbohydrate, e.g. isopropylidene derivatives, in the sulfation reaction. ... 

Chlorosulfonic acid reacts with 100% nitric acid (prepared by distillation of concentrated nitric acid and 30% oleum) to give nitryl chloride 6 (Equation 13). Chlorosulfonic acid (one equivalent) is added dropwise to stirred 100% nitric acid at 0 °C, and after half an hour at RT, nitryl chloride distils as a pale yellow liquid (bp —17 to — 18 C). Pure nitryl chloride is a colourless gas and this reaction provides the best synthetic route to the compound. ... 

Chlorosulfonic acid reacts with hydrogen peroxide in isoamyl alcohol to yield peroxymonosulfiiric acid 10 (Equation 17). The reaction involves nucleophilic attack by hydrogen peroxide on the electrophilic sulfur atom of chlorosulfonic acid. A peroxydisulfuric acid 11 can also be prepared by this route using excess chlorosulfonic acid (Equation 18), ... 

Several sulfonamides are useful in agriculture and are manufactured by procedures using chlorosulfonic acid (see also Chapter 6, ref 33) The sulfonylcarba-mate, asulam 19, used to kill docks and bracken in grassland, is synthesized from aniline via chlorosulfonation by reaction with chlorosulfonic acid (Scheme 4). The sulfonamide oryzalin 20 provides pre-emergence weed control in a wide range of agricultural crops. 

A polymer matrix of 75% polyethylene and 25% styrene divinyl benzene copolymer was chlorosulfonated by reaction with chlorosulfonic acid in dichloro-methane-dioxan-ethyl acetate mixture and subsequently treated with amines, e.g. aniline, butylamine, etc. The resultant sulfonamidopolymer membranes were useful cation-exchange materials having modified properties. ... 

In a stage of the synthesis, 4-(2-ethoxybenzamido)-l-methyl-3-propyl-pyrazole-5-carboxamide was chlorosulfonated by reaction with chlorosulfonic acid-thionyl chloride (18 hours) to yield 4-ethoxy-3-(5-aminocarbonyl-l-methyl-3-propylp5n-azol-4-yl) carbamoylbenzenesulfonyl chloride. In this reaction, sulfonation occurs preferentially para with respect to the more powerful electron-donating ethoxy group as would be anticipated (Chapter 6, Section 1.2.4). 

Chitosan was sulfonated by treatment with chlorosulfonic acid-formamide, in which the ratio of chitosan to formamide was 1 g 10 ml. Studies were made of the effects of the addition of chlorosulfonic acid, reaction temperature and time. The optimum conditions for the sulfonation were 4 ml of chlorosulfonic acid for 1 g of chitosan and a reaction temperature of 68 °C for 4 hours (see Chapter 5, Section 3.2). 

A series of fiber-reactive dyes have been made by the reaction of Sulforhodamine B with chlorosulfonic acid, an appropriately substituted diamine, and cyanutic chloride to yield dyes, eg, a Sulforhodamine B derivative (34), with good hghtfastness (42). 

Intermediate formation of formyl chloride is not necessary since the actual alkylating agent, HCO", can be produced by protonation of carbon monoxide or its complexes. However, it is difficult to obtain an equimolar mixture of anhydrous hydrogen chloride and carbon monoxide. Suitable laboratory preparations involve the reaction of chlorosulfonic acid with formic acid or the reaction of ben2oyl chloride with formic acid ... 

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