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Reduction sulfonation

HI, also give the reduction. Sulfonic acids have been reduced to thiols with a mixture... [Pg.1557]

Thiols can be prepared by the reduction of sulfonyl halides652 with LiAIH4. Usually, the reaction is carried out on aromatic sulfonyl chlorides. Zinc and acetic acid, and HI. also give the reduction. Sulfonic acids have been reduced to thiols with a mixture of triphenyl-phosphine and either Ii or a diaryl disulfide.633 Disulfides RSSR can also be produced.634 For the reduction of sulfonyl chlorides to sulfinic acids, see 0-118. [Pg.1221]

Fatty Acid. High-grade tall oil fatty acid is comprised essentially of oleic and linoleic acids in equal proportions. Typical carboxylic related reactions such as salt formation, esterification, amidization, reduction, sulfonation, sulfation, and ethylene oxide adduction are well-known. Since these reactions are common to all fatty acids, they will not be discussed further. However, there are a number of other more specific reactions applicable mainly to tall oil fatty acid that are significant industrially a brief review of these is in order. [Pg.1173]

The Julia-Lythgoc olefination operates by addition of alkyl sulfone anions to carbonyl compounds and subsequent reductive deoxysulfonation (P. Kocienski, 1985). In comparison with the Wittig reaction, it has several advantages sulfones are often more readily available than phosphorus ylides, and it was often successful when the Wittig olefination failed. The elimination step yields exclusively or predominantly the more stable trans olefin stereoisomer. [Pg.34]

Direct sulfonation of thiazole, as well as of 2-substituted thiazoles, leads mostly to substitution m the 5-position (330-332). 4-Thiazole sulfonic acid has been prepared through direct sulfonation of 2.5-dibromothiazole with subsequent Rane% Ni reduction (330). Sulfonation of 2.5-dimethyl- and 2-piperidyl-5-methylthiazoles affords the corresponding 4-sulfonic acids as barium salts (247). The 2-hydroxy group facilitates the sulfonation (201. 236). When the 4- and 5-positions are occupied direct sulfonation can occur in the 2-position. 5-hydroxyethyl-4-methyl-2-thiazole sulfonic acid has been prepared in this manner (7). [Pg.413]

Substitution. Substitution products retain the same nuclear configuration as naphthalene. They are formed by the substitution of one or more hydrogen atoms with other functional groups. Substituted naphthalenes of commercial importance have been obtained by sulfonation, sulfonation and alkah fusion, alkylation, nitration and reduction, and chlorination. [Pg.482]

Naphthalenesulfonic acids are important chemical precursors for dye intermediates, wetting agents and dispersants, naphthols, and air-entrainment agents for concrete. The production of many intermediates used for making a2o, a2oic, and triphenylmethane dyes (qv) involves naphthalene sulfonation and one or more unit operations, eg, caustic fusion, nitration, reduction, or amination. [Pg.489]

Many aminonaphthalenesulfonic acids are important in the manufacture of azo dyes (qv) or are used to make intermediates for azo acid dyes, direct, and fiber-reactive dyes (see Dyes, reactive). Usually, the aminonaphthalenesulfonic acids are made by either the sulfonation of naphthalenamines, the nitration—reduction of naphthalenesulfonic acids, the Bucherer-type amination of naphtholsulfonic acids, or the desulfonation of an aminonaphthalenedi-or ttisulfonic acid. Most of these processes produce by-products or mixtures which often are separated in subsequent purification steps. A summary of commercially important aminonaphthalenesulfonic acids is given in Table 4. [Pg.494]

By sulfonation of the appropriate naphthaleneamine or aminonaphthalenesulfonic acid. By nitration/reduction of the appropriate naphthalene (poly) sulfonic acid. [Pg.496]

Sodium Bisulfite. Sodium bisulfite [7631-90-5] NaHSO, is occasionally used to perform simultaneous reduction of a nitro group to an amine and the addition of a sulfonic acid group. For example, 4-amino-3-hydroxyl-l-naphthalenesulfonic acid [116-63-2] C qH NO S, is manufactured from 2-naphthol in a process which uses sodium bisulfite (59). The process involves nitrosation of 2-naphthol in aqueous medium, followed by addition of sodium bisulfite and acidification with sulfuric acid. [Pg.263]

An asymmetric synthesis of estrone begins with an asymmetric Michael addition of lithium enolate (178) to the scalemic sulfoxide (179). Direct treatment of the cmde Michael adduct with y /i7-chloroperbenzoic acid to oxidize the sulfoxide to a sulfone, followed by reductive removal of the bromine affords (180, X = a and PH R = H) in over 90% yield. Similarly to the conversion of (175) to (176), base-catalyzed epimerization of (180) produces an 85% isolated yield of (181, X = /5H R = H). C8 and C14 of (181) have the same relative and absolute stereochemistry as that of the naturally occurring steroids. Methylation of (181) provides (182). A (CH2)2CuLi-induced reductive cleavage of sulfone (182) followed by stereoselective alkylation of the resultant enolate with an allyl bromide yields (183). Ozonolysis of (183) produces (184) (wherein the aldehydric oxygen is by isopropyUdene) in 68% yield. Compound (184) is the optically active form of Ziegler s intermediate (176), and is converted to (+)-estrone in 6.3% overall yield and >95% enantiomeric excess (200). [Pg.436]

Sulfonic acids are prone to reduction with iodine [7553-56-2] in the presence of triphenylphosphine [603-35-0] to produce the corresponding iodides. This type of reduction is also facile with alkyl sulfonates (16). Aromatic sulfonic acids may also be reduced electrochemicaHy to give the parent arene. However, sulfonic acids, when reduced with iodine and phosphoms [7723-14-0] produce thiols (qv). Amination of sulfonates has also been reported, in which the carbon—sulfur bond is cleaved (17). Ortho-Hthiation of sulfonic acid lithium salts has proven to be a useful technique for organic syntheses, but has Httie commercial importance. Optically active sulfonates have been used in asymmetric syntheses to selectively O-alkylate alcohols and phenols, typically on a laboratory scale. Aromatic sulfonates are cleaved, ie, desulfonated, by uv radiation to give the parent aromatic compound and a coupling product of the aromatic compound, as shown, where Ar represents an aryl group (18). [Pg.96]

Catalytic reduction of secondary functionaUties in sulfonates, in which the sulfonate moiety is unchanged, is accompHshed using standard hydrogenation techniques (21). Sulfonic acids may be converted to the corresponding silyl esters in very high yields (22). [Pg.97]


See other pages where Reduction sulfonation is mentioned: [Pg.270]    [Pg.424]    [Pg.271]    [Pg.554]    [Pg.270]    [Pg.424]    [Pg.271]    [Pg.554]    [Pg.268]    [Pg.249]    [Pg.428]    [Pg.278]    [Pg.215]    [Pg.278]    [Pg.276]    [Pg.296]    [Pg.339]    [Pg.439]    [Pg.160]    [Pg.323]    [Pg.70]    [Pg.103]    [Pg.519]    [Pg.49]    [Pg.81]    [Pg.99]   
See also in sourсe #XX -- [ Pg.528 ]




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Alkyl sulfonates reduction

Allyl sulfones reductive desulfurization

Enol sulfonates reduction

Hydride reduction of sulfonates

Keto sulfones, reduction

Ketones, reductive cleavage sulfonation

Nitro groups, reduction sulfonic acids

REDUCTIVE ANNULATION OF VINYL SULFONES

Reduction of Vinyl Sulfones

Reduction of halides, sulfonates and epoxides

Reduction of sulfonates

Reduction of sulfones

Reduction vinyl sulfones

Reductions sulfonates, sodium borohydride

Reductive aliphatic sulfones

Reductive aminations, secondary amines, sulfonic acid

Reductive cleavage of sulfones

Reductive desulfonylation, of vinyl sulfone

Reductive elimination acetoxy sulfones

Reductive elimination, sulfone-based

Reductive trifluoromethylations, trifluoromethyl phenyl sulfone

Sodium amalgam reductive desulfurization of sulfones

Sulfonate esters, reduction

Sulfonated naphthalene water reduction

Sulfonates reduction

Sulfonates reduction

Sulfonates reduction reactions

Sulfonates reductive cleavage

Sulfonates, allylic reduction

Sulfone reduction

Sulfone reduction

Sulfones 1-hydroxy, reductive elimination

Sulfones dissolving metal reductions

Sulfones reduction

Sulfones reduction

Sulfones reductive cleavage

Sulfones reductive elimination

Sulfones reductive lithiation

Sulfones reductive removal

Sulfones unsaturated, reduction

Sulfones, alkylation reduction

Sulfones, allyl reduction

Sulfones, vinyl stereoselective reduction

Sulfonic acids reduction

Sulfonic acids reductive desulfurization

Sulfonic reduction

Sulfonic reduction

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