Thionyl chloride reaction with sulfonic acids

The a -halosulfone, required for the Ramberg-Backlund reaction, can for example be prepared from a sulfide by reaction with thionyl chloride (or with N-chlorosuccinimide) to give an a-chlorosulfide, followed by oxidation to the sulfone—e.g. using m-chloroperbenzoic acid. As base for the Ramberg-Backlund reaction have been used alkoxides—e.g. potassium t-butoxide in an etheral solvent, as well as aqueous alkali hydroxide. In the latter case the use of a phase-transfer catalyst may be of advantage. ... 

Sulfonyl chlorides (51) may also be obtained by heating the sulfonic acid or its sodium salt with thionyl chloride or phosphorus pentachloride (Scheme 31). The reaction with thionyl chloride is catalysed by the addition of a few drops of DMF. The chlorosulfonation of organic compounds may also be achieved by reaction with sulfur dioxide and chlorine this is an important industrial process (the Reed reaction) (Scheme 32). 

Pyridine-4-sulfonic acid. The formation of an arylsulfonic acid by reaction with thionyl chloride is a special reaction of pyridine derivatives a possible sequence of events is indicated in the formulation. ... 

A review of synthetic methods for the most popular photoactive compounds used in diazoquinone resists—DNQ-5-sulfonate and DNQ-4-sulfonate—has been provided by Ershov et al. The synthesis typically begins with naphthalene derivatives, and proceeds via introduction of a sulfonic acid group, followed by diazotization and reaction with thionyl chloride to yield the sulfonic acid chloride (Scheme 7.2). In the next step, the chloride is reacted in a base-catalyzed esterification with a suitable ballast group or backbone, which usually is a multifunctional phenol, less frequently a monofunctional phenol or an aliphatic alcohol. ... 

To prove the identity of sulfonic acids, fusion with sodium hydroxide and the qualitative analysis of the products, or the reaction with thionyl chloride (see p. 394), is usually applied. 

Sulfonic acids can be converted on reaction with thionyl chloride to corresponding chlorides, which on reaction with hydroxylamine change to sulfonyl-hydroxamic acids. These acids react in an alkaline medium with acetaldehyde with the formation of acetohydroxamic acids and sulfinic acids. Both products give colors with ferric chloride the first red, the second red-orange. 

An example of a sulfite ester made from thionyl chloride is the commercial iasecticide endosulfan [115-29-7]. A stepwise reaction of thionyl chloride with two different alcohols yields the commercial miticide, propaigite [2312-35-8] (189). Thionyl chloride also has appHcations as a co-reactant ia sulfonations and chlorosulfonations. A patent describes the use of thionyl chloride ia the preparation of a key iatermediate, bis(4-chlorophenyl) sulfone [80-07-9] which is used to make a commercial polysulfone engineering thermoplastic (see Polymers CONTAINING SULFUR, POLYSULFONe) (190). The sulfone group is derived from chlorosulfonic acid the thionyl chloride may be considered a co-reactant which removes water (see Sulfolanes and sulfones). 

A commonly used and important reaction of sulfonic acids, or sulfonates, is their conversion to sulfonyl chlorides by treatment with phosphorus halides, or sometimes with thionyl chloride. Although it is easy to postulate mechanisms for this conversion, the exact path followed has never been determined. Similarly, although mechanisms can be suggested for other known reactions involving sulfonic acids, such as the cleavage of dialkyl ethers by anhydrous sulfonic acids (Klamann and Weyerstahl, 1965), or the formation of sulfones by treatment of an aromatic hydrocarbon with a mixture of sulfonic acid plus polyphosphoric acid (Graybill, 1967), nothing truly definitive is known about the details of the actual mechanisms of these reactions. 

The reaction of methyl (3-hydroxypyridin-2-yl)ketone oxime (487) with thionyl chloride, trichloroacetyl isocyanate or chlorosulfonyl isocyanate gave 3-methylisoxazolo[4,5-6]pyridine (488) in varying yields dependent upon the temperature and solvent (Equation (43)) <87H(26)292l>. Trichloroacetyl isocyanate was particularly effective in the formation of compound (488) in either diethyl ether or tetrahydrofuran, at ambient temperature or at reflux, affording 60-78% yields. The treatment of 2-acetyl-3-hydroxypyridine (489) with hydroxyamine 0-sulfonic acid afforded a 1 1 mixture of compound (488) and 2-methyloxazolo[4,5-6]pyridine (490) (Equation (44)). The formation of the isomer (490) results from a Beckmann rearrangement. 

Aromatic sulfonyl chlorides can be prepared directly, by treatment of aromatic rings with chlorosulfuric acid. Since sulfonic acids can also be prepared by the same reagent (11-7), it is likely that they are intermediates, being converted to the halides by excess chlorosulfuric acid. The reaction has also been effected with bromo- and fluorosulfuric acids. Sulfinyl chlorides (ArSOCl) have been prepared by the reaction of thionyl chloride and an aromatic compound on Montmorillonite KIO clay. ii... 

Diaryl sulfoxides can be prepared by the reaction of aromatic compounds with thionyl chloride and triflic acid. Diaryl sulfones have also been prepared using... 

Thionyl chloride (39) in the presence of a few drops of DMF (catalyst) is a valuable reagent for the conversion of sulfonic acids (31) into the sulfonyl chlorides (32) (Scheme 32). This resembles the well-known reaction of thionyl chloride with carboxylic acids for the preparation of acyl chlorides, and has the advantage that both the by-products are gaseous. 

Treatment of benzothiazole with an excess of chlorosulfonic acid and then thionyl chloride affords a 4 1 mixture of the 4- and 7-sulfonyl chlorides, respectively. Chlorosulfonic acid alone fails to react with benzothiazole. This is probably due to the formation of the 4-sulfonic acid where an intramolecular hydrogen bond inhibits the formation of the chlorinated derivative <92PS(73)107>. Interestingly, when the same reaction is carried out with 2-methylbenzothiazole the major product is the 6-sulfonyl chloride. 

When pyridine is treated with thionyl chloride, a synthetically useful dichloride salt is formed, which can, for example, be transformed into pyridine-4-sulfonic acid. The reaction is believed to involve initial attack by sulfur at nitrogen, followed by nucleophilic addition of a second pyridine at C-4 (cf. 8.12.2). ... 

The present study reflects the re-design of a manufacturing process for the production of a copper phthalocyanine dye intermediate through a three step process involving synthesis, precipitation, and filtration. Figure 1 shows the reaction scheme for the original process. The sulfonation of copper phthalocyanine with chlorosulfonic acid is followed by a chlorination step with thionyl chloride that leads to the formation of the tetra-sulfonyl chloride dye intermediate. The product is isolated via a water precipitation (quenching) from the acidic solution followed by a filtration operation. 

If the reaction is carried out as a single-stage reaction starting from chlorobenzene, without isolation of the intermediate chlorobenzenesulfonyl chloride, care must be taken to ensure that sulfonic acid, thionyl chloride and sulfur chlorides, as impurities in the thionyl chloride, are no longer present in the reaction mixture, since the free sulfonic acid causes deactivation of the catalyst, and thionyl chloride and sulfur chlorides Ukewise lead to undesirable byproducts. A further difficulty is that iVA -dimethyl-formamide is required for complete conversion of chlorobenzenesulfonic acid with thionyl chloride into the corresponding sulfonyl chloride, carcinogenic A,A-dimethylcarbamyl chloride being formed as a byproduct. 

When a sulfonic acid such as butanesulfonic acid (111 see Chapter 16, Section 16.9) is treated with thionyl chloride or phosphorus trichloride, the product is a sulfonyl chloride. In this case. 111 is converted to what is known as butanesulfonyl chloride, 112. When 112 reacts with an alcohol, a sulfonate ester is produced. Treatment of 112 with ethanol leads to 113 (ethyl butanesul-fonate) and treatment with methanol leads to 114 (methyl butanesulfonate). A variety of sulfonate esters can be prepared in this manner. It is also possible to react a sulfonic acid with an alcohol under acid catalysis conditions to give sulfonate esters, but that reaction is not discussed until Chapter 20. 

Chlorobenzene reacts with an equimolar amount of chlorosulfonic acid to give mainly the p-sulfonic acid together with a little of the sulfonyl chloride and the sulfone. With an excess of the reagent good yields of p-chlorobenzenesulfonyl chloride are obtained. The kinetics of the sulfonation of chlorobenzene with chlorosulfonic acid have been studied, and the reaction has been reported in several patents. These involved various modifications such as the use of excess reagent in hydrocarbon solvents containing alkali metal or ammonium salts, or a mixture of the reagent with thionyl chloride in the presence of sulfamic acid, sodium sulfate or dimethylformamide. In the reaction, the yield of 4,4 -dichlorodiphenyl sulfone can be increased under a variety of conditions the... 

An improved procedure for the chlorosulfonation of substituted diaryl sulfones involves heating the appropriate 4,4 -dialkyl or dihalodiaryl sulfone with chlorosulfonic acid (2-4 equivalents) at 140-150 °C and subsequent treatment with thionyl chloride (6-10 equivalents). The action of chlorosulfonic acid on propiophenone (ethyl phenyl ketone 226) results in a novel cyclization reaction yielding 3-chloro-2-methylbenzothiophene-1,1-dioxide 227 (Scheme 2). The reagent similarly caused smooth cyclization of Mannich bases 228, the reaction again proceeding via the enolic sulfonic acid to yield the cyclic sulfone 229 (Equation 72). ... 

C for 3 hours, followed by refluxing with thionyl chloride-DMF (catalyst) for 2 hours and ti eatment with amines to give the corresponding pam-sulfonamides 159 (39-68%) (Equation 41). In this reaction, the conversion of the initially formed sulfonic acid into the sulfonyl chloride was comparatively slow and the sulfonyl chloride was not isolated, but was immediately converted into the corresponding sulfonamides. 2-Styrylbenzoxazole 160 similarly reacted with excess chlorosulfonic acid (six equivalents) at RT (Iweek) to give the p-sulfonyl chloride which was again not isolated, but was converted into the sulfonamides 161, 41-68% (Equation 42)." ... 

Karimi et al. reported a variety of water-tolerant ordered nanoporous silicas functionalized with sulfonic acids for the Pechmann reaction, satisfying both recyclability and reactivity [65]. More recently, some of the authors developed a new family of periodic mesoporous silica chloride (PMSCl) synthesized by direct chlorination of SBA-15 with thionyl chloride the resulting material with 2D-hexagonal symmetry showed both high loading of Si-Cl moieties and thermal stability [66]. PMSCl efficiently catalyzed the synthesis of coumarins from a variety of phenols and ethyl acetoacetate, at 403 K, even much more than other sulfonic acids supporting mesoporous silicas, yielding coumarin 17 in almost quantitative yield in only Ih of reaction time. 

Sulfonyl and Sulfinyl Chlorides from Sulfonic and Sulfinic Acids. Alkyl or arylsulfonyl chlorides are prepared by heating the acid with thionyl chloride DMF catalyzes this reaction. (+)-Camphorsulfonyl chloride is produced in 99% yield without a catalyst. Use of the salts of sulfinic acids minimizes their oxidation p-toluenesulfinyl chloride is produced in about 70% yield from sodium p-toluenesulfinate dihydrate with excess thionyl chloride. Phosphorus(V) Chloride is more commonly used for this transformation. 

Sulfonic acids and carboxylic acids can be converted into their acid chlorides by treatment with phosphorus pentachloride or phosphorus oxychloride. Thionyl chloride, SOCl is effective for the synthesis of acyl chlorides, and sulfonyl chlorides can be prepared directly from the aromatic compound by reaction with an excess of chlorosulfonic acid. The acid chlorides are efficient Friedel-Crafts acylating agents, yielding sul-... 

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