Sulfur dioxide reaction with

This reaction seties continues until the last polysulfide is ammonium sulfide and the process is completed by reaction with sulfur dioxide ... 

The use of excess diazoalkane in its reaction with sulfur dioxide will necessarily lead to symmetrically substituted thiirane dioxides. When monoalkyl or monoaryl diazoalkanes are used, mixtures of cis- and trans-isomers are formed18-19-99. 

Anthocyanins usually give a purple red colour. Anthocyanins are water soluble and amphoteric. There are four major pH dependent forms, the most important being the red flavylium cation and the blue quinodial base. At pHs up to 3.8 commercial anthocyanin colours are ruby red as the pH becomes less acid the colour shifts to blue. The colour also becomes less intense and the anthocyanin becomes less stable. The usual recommendation is that anthocyanins should only be used where the pH of the product is below 4.2. As these colours would be considered for use in fruit flavoured confectionery this is not too much of a problem. Anthocyanins are sufficiently heat resistant that they do not have a problem in confectionery. Colour loss and browning would only be a problem if the product was held at elevated temperatures for a long while. Sulfur dioxide can bleach anthocyanins - the monomeric anthocyanins the most susceptible. Anthocyanins that are polymeric or condensed with other flavonoids are more resistant. The reaction with sulfur dioxide is reversible. 

Aquaclaus A modification of the Claus process in which hydrogen sulfide is removed from water by reaction with sulfur dioxide. Developed by Stauffer Chemical Company and operated by the Heflin Oil Company, in Queen City, TX. 

Claus A process for removing hydrogen sulfide from gas streams by the catalyzed reaction with sulfur dioxide, producing elementary sulfur. The process has two stages in the first, one third of the hydrogen sulfide is oxidized with air to produce sulfur dioxide in the second, this sulfur dioxide stream is blended with the remainder of the hydrogen sulfide stream and passed over an iron oxide catalyst at approximately 300°C. The resulting sulfur vapor is condensed to liquid sulfur. 

Reaction with sulfur dioxide yields thionyl chloride and phosphoryl chloride ... 

The lithio derivatives of dibenzofuran undergo the expected reactions. Carbonation yields carboxylic acids,reaction with sulfur dioxide yields sulfinic acids, and reaction with methyl sulfate yields methyl compounds. Alkylation can also be achieved by treatment of 4-lithio-dibenzofuran with alkyl halides. Silylation can be achieved with chlorotrimethyl- or chlorotriphenylsilane. " " Reaction of lithiodibenzo-furans with acetaldehyde and with benzonitrile take the expected course. 

Enzyme chemistry, 291 Enzyme substrate, 291 Epoxides, reaction with sulfur dioxide, 78-79... 

Lithiation of dibenzofuran with butyllithium and mercuration both occur at the 4-position. Thallation occurs at the 2-position, however (57IZV1391). The mercury and thallium derivatives serve as a source of the iodo compounds by reaction with iodine. Bromodibenzofurans undergo bromine/lithium exchange with butyllithium and the derived lithio compounds may be converted into phenols by reaction with molecular oxygen in the presence of a Grignard reagent, into amines by reaction with O-methylhydroxylamine, into sulfinic acids by reaction with sulfur dioxide, into carboxylic acids by reaction with carbon dioxide and into methyl derivatives by reaction with methyl sulfate (Scheme 100). This last reaction... 

The analogous reaction with sulfur dioxide has also been repox led by Kazuvaev and oo-workers,2088 using ethyleno oxide, propylew oxide, epichlorohydrin, and glycidol, and triethylammomum bromide or oilier salts as catalysts (Eq. 974a). 

Cyclopropylcarbinyl)Fp undergoes a formal 4+1 reaction with sulfur dioxide to give the corresponding sulfone, and a 4+2 reaction with TCNE to give a 6-membered ring... 

The availability of o-benzoylbenzenesulfonyl chlorides, prepared by diazotization of o-aminobenzophenones followed by reaction with sulfur dioxide in the presence of cuprous ions, can be exploited in the reaction with hydrazine or methylhydrazine to give 1,2,3-benzothiadiazine 14. Product 14 (R1 = Me) can also be obtained by methylationof 14(R = H) with methyl iodide and sodium hydroxide. The reduced form 15 results from catalytic hydrogenation of 14 (R = H, R2 = H)(68JHC453). Hydra-zobenzene reacts with 2-chlorosulfonylbenzoyl chloride in the presence of triethylamine to give diphenyl derivative 16 (79MI1). 3,1,2-Benzothia-... 

Of the large number of possible ways of synthesizing alkanesulfonates, only sulfochlorination of alkanes (conversion with sulfur dioxide and chlorine to form alkane sulfonyl chlorides and their saponification with sodium hydroxide Table 1, entry 10) and sulfoxidation (reaction with sulfur dioxide and oxygen and neutralization of the sulfonic acids Table 1, entry 11) are of industrial importance [18]. 

Kuri, Z., and H. Ueda Electron spin resonance studies of the radicals produced in high polymers by y-irradiation and their reaction with sulfur dioxide. J. Polymer Sci. 50, 349 (1961). 

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