Sulfinic acid chlorides esters

Thiolsulfinic acid esters from sulfinic acid chlorides... 

The most commonly employed routes for the preparation of the / -sulfatoethylsulfone group, which is the essential structural feature of vinylsulfone reactive dyes, are illustrated in Scheme 8.5. One method of synthesis involves, initially, the reduction of an aromatic sulfonyl chloride, for example with sodium sulfite, to the corresponding sulfinic acid. Subsequent condensation with either 2-chloroethanol or ethylene oxide gives the / -hydroxyethylsulfone, which is converted into its sulfate ester by treatment with concentrated sulfuric acid at 20 30 °C. An alternative route involves treatment of an aromatic thiol with 2-chloroethanol or ethylene oxide to give the /Miydroxyethylsulfonyl compound which may then be converted by oxidation into the /Miydroxyethylsulfone. 

A variant that eliminates the production of water and that has proved effective for esterification of hydroxy and aromatic amino acids involves the use of thionyl chloride instead of acid. At a low temperature, the alcohol reacts with the chloride, generating methyl sulfinyl chloride, which produces the ester, probably through the mixed carboxylic acid-sulfinic acid anhydride (Figure 3.18, B). p-Toluenesulfonyl chloride added to the acid and benzyl alcohol serves the same purpose in the preparation of benzyl esters. 

Buffer catalysis of the hydrolysis of phenyl (311 R = Ph) and methyl (311 R = Me) benzenesulfinates to give the sulfinic acid (312) and alcohol ROH is strongly accelerated by both carboxylate and amine components of the buffer which give Bronsted /i values of approximately unity on separate lines. The carboxylates are about 44 tunes more effective than amines of similar basicity. A concerted. S n2 mechanism with a hypervalent intermediate (313) is proposed for the nucleophilic reaction of these esters.286 The reaction of the thiosulfinate esters (314) with sulfenyl chlorides RSCI and sulfenate esters (315) to give sulfinyl chlorides and disulfides and sulfinate esters and disulfides, respectively, has been studied.287 Hydrolysis of 2-(3-aminophenyl)sulfonyl-ethanol hydrogensulfate gives under different conditions various products such as the ether (316) and the sulfone (317).288... 

Arylsulfonyl chlorides are pivotal precursors for the preparation of many diverse functional types including sulfonate esters,8 amides,4 sulfones,9 sulfinic acids,10 and others.11 Furthermore, sulfonyl fluorides are best prepared from sulfonyl chlorides.12 The sulfonyl fluorides have many uses, among which is their utilization as active site probes of chymotrypsin and other esterases.13 The trifluoromethyl group also plays valuable roles in medicinal chemistry.14... 

Sulfinyl chlorides (13) may be obtained by treatment of the sulfinic acid or the sodium salt with thionyl chloride (Scheme 9). In most cases, the best synthetic route involves chlorination of a solution of the corresponding thiol ester (14) in acetic anhydride (Scheme 10). 

Sulfinic acids and derivatives RS(0)0H, RS(0)X benzenesulfinic acid, p-toluenesufinyl chloride, other arenesulfinate esters and salts. 

The preparation of sulfinic acids by fission of the S-S bond of thiosulfonic salts or esters is useful when other methods are excluded by the presence of sensitive substituents. Arenethiosulfonic acid salts, which are formed from arenesulfonyl chlorides and alkali sulfides ... 

Sulfinyl chlorides, analogously to sulfonyl chlorides, are important starting materials for the preparation of other sulfinic acid derivatives. Thus, when warmed with alcohols they give sulfinic esters,712 713 and esterification can also be carried out by the Schotten-Baumann procedure in the presence of pyridine or potassium carbonate.714... 

The utility of methanesulfinyl chloride lies in its great chemical reactivity. Through its ready hydrolysis, it serves as a convenient source of methanesulfinic acid. It reacts at low temperature with aromatic amines to form sulfinamides, and with alcohols to form sulfinate esters. When it is hydrolyzed in the presence of an equimolar quantity of sulfenyl chloride, a thiol-sulfonate ester is produced. 

Sulfenyl chlorides react with zincalkyl (or -aryl) sulfinates and also with sodium benzene sulfinate to yield the corresponding esters of thiosulfonic acid 13, 111, 161) ... 

On the pages which follow, general methods are illustrated for the synthesis of a wide variety of classes of organic compounds including acyl isocyanates (from amides and oxalyl chloride p. 16), epoxides (from reductive coupling of aromatic aldehydes by hexamethylphosphorous triamide p. 31), a-fluoro acids (from 1-alkenes p. 37), 0-lactams (from olefins and chlorosulfonyl isocyanate p. 51), 1 y3,5-triketones (from dianions of 1,3-diketones and esters p. 57), sulfinate esters (from disulfides, alcohols, and lead tetraacetate p. 62), carboxylic acids (from carbonylation of alcohols or olefins via carbonium-ion intermediates p. 72), sulfoxides (from sulfides and sodium periodate p. 78), carbazoles... 

Preparative Methods obtained by reaction of (—)-menthol with p-toluenesulfinyl chloride. This esterification showed no particular stereoselectivity, giving an equal amount of the two sulfinate diastereomers. In order to avoid a chromatographic separation, it is possible to epimerize these sulfinate esters in acidic medium and displace the resulting equilibrium towards the less soluble isomer, (—)-menthyl (5)-p-toluenesulfinate, in 80% yield (eq 1). This procedure was later extended to large scale preparation. ... 

A simple method of preparing sulfinic esters consists of oxidative chlorination of aliphatic thiols, thiophenols, or disulfides with chlorine in glacial acetic acid, followed by alcoholysis of the resulting sulfinyl chlorides 626... 

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