Sulfonyl chloride from sulfonic acid

SUCCINONITRILE, a,/3-DIPHENYL-, 32, 63 Sulfonyl chloride from sulfonic acid, 30, 58... 

These acids are less stable, less soluble and less acidic than the corresponding sulfonic acids. The common impurities are the respective sulfonyl chlorides from which they have been prepared, and the thiolsulfonates (neutral) and sulfonic acids into which they decompose. The first two of these can be removed by solvent extraction from an alkaline solution of the acid. On acidification of an alkaline solution, the sulfinic acid crystallises out leaving the sulfonic acid behind. The lower molecular weight members are isolated as their metal (e.g. ferric) salts, but the higher members can be crystallised from water (made slightly acidic), or alcohol. 

These results suggest that the starting material did not give sodium pyrrole-2-sulfonate, but 3-sulfonate 420 (Scheme 89), or that rearrangement occurred in the formation of sulfonyl chloride from pyrrole-2-sulfonate to afford pyrrole-3-sulfonyl chloride 421 or in a cyclization step of 2-substituted acid 426. 

Sommelet reaction, 33, 93 Sorbic acid, 5-hydroxy-/3-methyl, J-lactone, 32, 57 Stannic chloride, 33, 91 Stearic acid, 34, 15 Stearone, 33, 84 cis-Stilbene, 33, 88 fraws-Stilbene, 33, 89 Stirrer, for caustic fusion, 30, 104, 105 seal for, 30, 54 Stobbe condensation, 30, 18 Styrene, 33, 72 34, 85 reaction with sulfuric acid, 35, 83 Styrene dibromide, 30, 73 Styrene oxide, 31, 3 0-Styrenesulfonyl chloride, 34, 85 Succinic acid, 34, 44 Succinic acid, < -benzhydrylidene-, a-ETHYL ESTER, 30, 18 CLNNAMYL-, 31, 85 DIPHENYL ESTER, 34, 44 HEPTANOYL-, DIETHYL ESTER, 34, 51 PHENYL-, 30, 83 Succinic anhydride, 34, 40 SUCCINONITRILE, a, -DIPHENYL-, 32, 63 Sulfide, methyl 2-thienyl, 35, 85 Sulfonation of styrene, 34, 85 Sulfonyl chloride, from sodium sulfonate, 34, 85... 

Sulfonyl chlorides can also be obtained by means of SOCl2-dimethyl-formamide, from sulfonic acids or their Na salts. 

As mentioned above, the chlorosulfonyl group cannot be introduced into aromatic hydrocarbons by Reed s process, but this can be achieved by means of the chlorides from sulfuric acid.213 Preparation of sulfonyl chlorides by means of chlorosulfuric acid depends on using a sufficient excess and on the purity of the acid sulfones may be formed as by-products, and these can be further sulfochlorinated.214 Benzenesulfonyl chloride has been prepared from benzene in 75-77% yield in this way.215... 

Preparation of many other sulfonyl chlorides from the sulfonic acids is covered in a review by Suter.152b... 

In Figure 11.2, a sulfonate ester is the leaving group, and reaction with a nucleophile breaks the weaker C-0 bond to generate a sulfonate anion (26). This anion is resonance stabilized and quite stable, which means it is relatively unreactive as a nucleophile. The combination of a weak C-0 bond and the stability and poor reactivity of the sulfonate anion makes sulfonate esters good leaving groups. The most common sulfonate esters (see Chapter 20, Section 20.11) are those derived from methanesulfonic acid, benzenesulfonic acid, or 4-methylbenzenesulfonic acid. Formation of sulfonate esters from sulfonic acids or sulfonyl chlorides will be discussed in Section 11.7.3 and in Chapter 20,... 

As we have just seen, alcohols react with thionyl chloride to form alkyl chlorosulfites. Alcohols also react with compounds called sulfonyl chlorides to form alkylsulfonates. Sulfonyl chlorides are derived from sulfonic acids, which are comparable in strength to sulfuric acid. 

In sulfonation, disulfonation may occur and also formation of byproducts when free sulfur trioxide is present, e.g. sulfonic anhydrides (from intermolecular dehydration of monosulfonic acids or from intramolecular dehydration of ortho-disulfonic acids). Sulfones may also be produced by electrophilic substitution by the sulfonic acid or by the sulfonyl chloride when chlorosulfonic acid is the sulfonating reagent the latter reagent also tends to form sulfonyl chlorides as byproducts. 

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. 

All the sulfonic acid hydrazides are made from hydrazine or semicarbazide and the appropriate sulfonyl chloride in the presence of an HCl acceptor such as ammonia. 

Phthalocyanine sulfonic acids, which can be used as direct cotton dyes (1), are obtained by heating the metal phthalocyanines in oleum. One to four sulfo groups can be introduced in the 4-position by varying concentration, temperature, and reaction time (103). Sulfonyl chlorides, which are important intermediates, can be prepared from chlorosulfonic acid and phthalocyanines (104). The positions of the sulfonyl chloride groups are the same as those of the sulfonic acids (103). Other derivatives, eg, chlormethylphthalocyanines (105—107), / /f-butyl (108—111), amino (112), ethers (109,110,113—116), thioethers (117,118), carboxyl acids (119—122), esters (123), cyanides (112,124—127), and nitrocompounds (126), can be synthesized. 

Pivalates. The selective pivaloylation of sucrose with pivaloyl (2,2-dimethylpropionyl) chloride has been thoroughly investigated (56). The reactivity of sucrose toward pivaloylation was shown to be significantly different from other sulfonic or carboxyflc acid chlorides. For example, reaction of sucrose with four molar equivalent of toluene-/)-sulfonyl chloride in pyridine revealed, based on product isolation, the reactivity order ofO-6 0-6 > 0-1 > 0-2 (57). In contrast, a reactivity order for the pivaloylation reaction, under similar reaction conditions, was observed to be 0-6 0-6 > 0-1 > 0-4. 

General Reaction Chemistry of Sulfonic Acids. Sulfonic acids may be used to produce sulfonic acid esters, which are derived from epoxides, olefins, alkynes, aHenes, and ketenes, as shown in Figure 1 (10). Sulfonic acids may be converted to sulfonamides via reaction with an amine in the presence of phosphoms oxychloride [10025-87-3] POCl (H)- Because sulfonic acids are generally not converted directiy to sulfonamides, the reaction most likely involves a sulfonyl chloride intermediate. Phosphoms pentachlotide [10026-13-8] and phosphoms pentabromide [7789-69-7] can be used to convert sulfonic acids to the corresponding sulfonyl haUdes (12,13). The conversion may also be accompHshed by continuous electrolysis of thiols or disulfides in the presence of aqueous HCl [7647-01-0] (14) or by direct sulfonation with chlorosulfuric acid. Sulfonyl fluorides are typically prepared by direct sulfonation with fluorosulfutic acid [7789-21-17, or by reaction of the sulfonic acid or sulfonate with fluorosulfutic acid. Halogenation of sulfonic acids, which avoids production of a sulfonyl haUde, can be achieved under oxidative halogenation conditions (15). 

Finally, certain 3-substituted compounds can be prepared by utilizing the - meta) directing powet (cf. Section IV,B) of some groups in the 2-position which afterward can be removed. 3-Nitrothiophene is prepared by nitration of 2-thiophenesulfonyl chloride and by removal of the sulfonic acid group of the 4-nitro-2-sulfonyl chloride formed with superheated steam. Another approach to 3-nitrothio-phene is to nitrate 2-cyanothiophene, separate the 4-nitro-2-cyano-thiophene from the 5-isomer, hydrolyze, and decarboxylate. A final method of preparation of 3-nitrothiophene is by simultaneous de-bromination and decarboxylation of 5-bromo-4-nitro-2-thiophene-carboxylic acid obtained through the nitration of methyl 5-bromo-2-thiophenecarboxylate. 

The antiparasitic drug clorsulon (206), contains a rather unusual trichloroethylene group. This function is established early in the syntliesis by treatment of the perhalogenated compound 203 obtained from reduction of 202 with iron powder. Chlorosulfonation of 204 by means of chloro-sulfonic acid, followed by conver.sion of. sulfonyl chloride 205 to the amide, gives clorsulon (206) 153],... 

This reaction, parallel with 10-77, is the standard method for the preparation of sulfonyl halides. Also used are PCI3 and SOCI2, and sulfonic acid salts can also serve as substrates. Sulfonyl bromides and iodides have been prepared from sulfonyl hydrazides (ArS02NHNH2, themselves prepared by 10-126) by treatment with bromine or iodine.Sulfonyl fluorides are generally prepared from the chlorides, by halogen exchange. 

Diaryl sulfones can be formed by treatment of aromatic compounds with aryl sulfonyl chlorides and a Friedel-Crafts catalyst. This reaction is analogous to Friedel-Crafts acylation with carboxylic acid halides (11-14). In a better procedure, the aromatic compound is treated with an aryl sulfonic acid and P2O5 in polypho-sphoric acid. Still another method uses an arylsulfonic trifluoromethanesulfonic anhydride (ArS020S02CF3) (generated in situ from ArS02Br and CF3S03Ag) without a catalyst. ... 

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