Sulfoxylates

H2NO2 nitroxylic acid H2SO2 sulfoxylic acid... 

Physical Properties. Sodium dithionite (sodium hydrosulfite, sodium sulfoxylate), Na2S204, is a colorless soHd and is soluble in water to the extent of 22 g/100 g of water at 20°C. 

In addition to appHcations in dyeing, sodium formaldehyde sulfoxylate is used as a component of the redox system in emulsion polymerization of styrene—butadiene mbber recipes. 

Another hydrosulfite reducing agent is zinc formaldehyde sulfoxylate, Zn(HS02-CH20)2 (see Bleaching agents). 

Properties of zinc salts of inorganic and organic salts are Hsted in Table 1 with other commercially important zinc chemicals. In the dithiocarbamates, 2-mercaptobenzothiazole, and formaldehyde sulfoxylate, zinc is covalendy bound to sulfur. In compounds such as the oxide, borate, and sihcate, the covalent bonds with oxygen are very stable. Zinc—carbon bonds occur in diorganozinc compounds, eg, diethjizinc [557-20-0]. Such compounds were much used in organic synthesis prior to the development of the more convenient Grignard route (see Grignard reactions). 

The reducing agents generally used in bleaching include sulfur dioxide, sulfurous acid, bisulfites, sulfites, hydrosulfites (dithionites), sodium sulfoxylate formaldehyde, and sodium borohydride. These materials are used mainly in pulp and textile bleaching (see Sulfur compounds Boron compounds). 

Halogenation of sulfoxylated fibers yields materials with excellent dame-retardant properties (32). 

Reduction. Many dyes, particularly azo dyestuffs, are susceptible to destmctive reduction. The reducing agents that can be used are sodium hydrosulfite, thiourea dioxide, sodium borohydtide, zinc sulfoxylate, and ferrous iron. 

Sodium formaldehyde sulfoxylate dihydrate (sodium hydroxymethylsulHnate, Rongalite)... 

In the presence of sodium bicarbonate, sodium formaldehyde sulfoxylate (Rongalite) converts perfluoroalkyl iodides and bromides to the corresponding carboxylates Less decarboxylation to the monohydroperfluoroalkanes occurs when the bromides are used [16] (equation 17)... 

Synthesis, structure, transformations, and applications of sulfoxylic acid (HOSOH) derivatives containing heterocyclic fragments 98ZOR1433. 

About 20 grams of diamino diphenyl sulfone is dissolved in about 500 cc of ethyl alcohol (3A made up of 5 parts methyl alcohol and 100 parts of ethyl alcohol) by placing the ingredients in a flask provided with a reflux condenser and warming over a water bath. About 24 grams of pure grade, very finely powdered (40 to 60 mesh) sodium formaldehyde sulfoxylate Is then rapidly added to the alcohol solution of diamino diphenyl sulfone and the mixture refluxed in the usual manner. It was found that the mixture should be refluxed for a total of 5 hours and that a precipitate starts to form near the 3 hour period. The reaction mixture is then cooled to 15°C and kept at this temperature for about 1 hour. The precipitate formed in the filtrate is filtered off rapidly and drained as much as possible to remove mother liquor and then washed with small amounts of cold alcohol. The solid product is immediately placed in a desiccator and dried over sulfuric acid for about 20 hours. 

Principally, both unifold and twofold transformation types ensue in these cases. A unifold transformation occurs in the case of the rearrangement of cumyl benzenesulfinate, which arises from the conversion of cumyl hydroperoxide with benzenesulfenyl chloride23 (equation 2). Closely related sulfoxylate-sulfone rearrangements, which pass intermediate sulfinate steps similarly, are equally known24,25. 

Between sulfur dioxide radical anions, dithionite, and sulfoxylate/sulfite there exists a pH-dependent equilibrium465 (equation 86). Therefore, dithionite has been used as a source of sulfoxylate in order to prepare sulfinate and hence sulfones. Alkylation with triethyl oxonium fluoroborate leads to ethyl ethanesulfinate, alkyl iodides lead to symmetrical sulfones466 (equation 87). 

On the other hand, Michael-acceptor olefins add to the sulfoxylate stage from dithionite, yielding a sulfinate intermediate which yields, according to the reaction... 

D. The Double [2,3]Sigmatropic Rearrangement of Allylic and Propargylic Sulfoxylates... 

Interestingly, the somewhat analogous benzyl sulfoxylate (5) has been reported to readily undergo rearrangement in low yield to benzyl a-toluenesulfinate (6) during preparation (equation 5)32. 

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