Aromatic Mercaptans

Coal Total Sulfur (wt %) Organic Sulfur (wt %) Aliphatic Sulfides Mercaptans Aromatic Sulfides (3) Mercaptans % of Organic Sulfur Thiophenic Heating value (BTU/lb) Pyrite (wt %)... 

Classification Aromatic mercaptan aromatic thiol Empirical C7H8S Formula C6H5CH2SH... 

The reaction of aliphatic and aromatic mercaptans with aziridines yields thioethers (117—119). 

The close electrochemical relationship of the simple quinones, (2) and (3), with hydroquinone (1,4-benzenediol) (4) and catechol (1,2-benzenediol) (5), respectively, has proven useful in ways extending beyond their offering an attractive synthetic route. Photographic developers and dye syntheses often involve (4) or its derivatives (10). Biochemists have found much interest in the interaction of mercaptans and amino acids with various compounds related to (3). The reversible redox couple formed in many such examples and the frequendy observed quinonoid chemistry make it difficult to avoid a discussion of the aromatic reduction products of quinones (see Hydroquinone, resorcinol, and catechol). 

M-iscellaneousFxtractions. Additional extractive separations using sulfolane involve (/) mercaptans and sulfides from sour petroleum (45) (2) /-butylstyrene from /-butylethjlbenzene (46) (J) mixtures of close boiling chlorosHanes (47) and (4) aromatics from kerosene (48—50), naphtha (49,51—53), and aviation turbine fuel (54). 

In addition to combined hydrogen and oxygen, carbon blacks may contain as much as 1.2% combined sulfur resulting from the sulfur content of the aromatic feedstock that contains thiophenes, mercaptans, and sulfides. The combined sulfur appears to be inert and does not contribute to sulfur cross-linking during the vulcanization of mbber compounds. 

Paint and varnish manufacturing Resin manufacturing closed reaction vessel Varnish cooldng-open or closed vessels Solvent thinning Acrolein, other aldehydes and fatty acids (odors), phthalic anhydride (sublimed) Ketones, fatty acids, formic acids, acetic acid, glycerine, acrolein, other aldehydes, phenols and terpenes from tall oils, hydrogen sulfide, alkyl sulfide, butyl mercaptan, and thiofen (odors) Olefins, branched-chain aromatics and ketones (odors), solvents Exhaust systems with scrubbers and fume burners Exhaust system with scrubbers and fume burners close-fitting hoods required for open kettles Exhaust system with fume burners... 

Effect of Catalyst The catalysts used in hydrotreating are molybdena on alumina, cobalt molybdate on alumina, nickel molybdate on alumina or nickel tungstate. Which catalyst is used depends on the particular application. Cobalt molybdate catalyst is generally used when sulfur removal is the primary interest. The nickel catalysts find application in the treating of cracked stocks for olefin or aromatic saturation. One preferred application for molybdena catalyst is sweetening, (removal of mercaptans). The molybdena on alumina catalyst is also preferred for reducing the carbon residue of heating oils. 

Aliphatic methyl ketones (CH3C(0)CH3) Simple aromatic nitro compounds (NO+CO) Straight-chain mercaptans Thiocyanates and isothiocyanates... 

Homoallyl mercaptans react with aromatic aldehydes in an InC -mediated Prins cyclisation to give substituted tetrahydrothiopyrans 85 with good diastereoselectivity (Scheme 57) <00TL1321>. 

MERIFINING A process for extracting aromatic mercaptans and organic acids from cracked hydrocarbon fractions by aqueous alkali, using a bundle of hollow fibers. Developed by the Merichem Company, Houston, TX. Twelve units were operating as of 1991. 

Dinitrobenzenesulfenyl chloride is a versatile analytical reagent for the characterization of a wide variety of organic compounds, including alcohols, mercaptans, ketones, olefins, amines, aromatic compounds, olefin oxides, and hydroxysteroids. Review articles summarize these applications.9 10... 

Weakly adsorbed Alkenes, mercaptans, sulfides, aromatics, and halogenated aromatics... 

The thioalcohols have a pronounced acidic character. The alkali salts of the aliphatic mercaptans are, indeed, very largely hydrolysed by water, but the aromatic compounds, on the other hand, can be... 

The aromatic mercaptans react with chlorine to form aryl sulphur chlorides (Zincke) phenyl sulphur chloride is a deep red, very reactive liquid (Lecher) ... 

In addition, iodine snccessfnlly catalyzed the electrophilic snbstitntion reaction of indoles with aldehydes and ketones to bis(indonyl)methanes [225], the deprotection of aromatic acetates [226], esterifications [227], transesterifications [227], the chemoselective thioacetalization of carbon functions [228], the addition of mercaptans to a,P-nnsatnrated carboxylic acids [229], the imino-Diels-Alder reaction [230], the synthesis of iV-Boc protected amines [231], the preparation of alkynyl sngars from D-glycals [232], the preparation of methyl bisnlfate [233], and the synthesis of P-acetamido ketones from aromatic aldehydes, enolizable ketones or ketoesters and acetonitrile [234],... 

Recent work ( ) with model organosulphur compounds has shown that at temperatures above 350 C and pressures in excess of 100 atm (1500 psig), the hydrolytic desulphurisation reaction occurs readily with thioethers, mercaptans and other non-thio-phenic types of organosulphur compounds. Thiophene itself is more resistant to this type of reaction but desulphurisation is significant in the 450 - 500 C range. More complex fused ring sulphur containing aromatic structures, can, however, be more reactive. 

Fairchild EJ, Stokinger HE Toxicologic studies on organic sulfur compounds. 1. Acute toxicity of some aliphatic and aromatic thiols (mercaptans). Am Ind Elyg Assoc J 19 171-189, 1958... 

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