Trichloromethane anion

Not many reactions between A-(l-haloalkyl)heteroarylium halides and anionic nucleophiles are reported in the literature. In trichloromethane or... 

Active matter (anionic surfactant) in AOS consists of alkene- and hydroxy-alkanemonosulfonates, as well as small amounts of disulfonates. Active matter (AM) content is usually expressed as milliequivalents per 100 grams, or as weight percent. Three methods are available for the determination of AM in AOS calculation by difference, the two-phase titration such as methylene blue-active substances (MBAS) and by potentiometric titration with cationic. The calculation method has a number of inherent error factors. The two-phase titration methods may not be completely quantitative and can yield values differing by several percent from those obtained from the total sulfur content. These methods employ trichloromethane, the effects from which the analyst must be protected. The best method for routine use is probably the potentiometric titration method but this requires the availability of more expensive equipment. 

The amount of residual sulfonate ester remaining after hydrolysis can be determined by a procedure proposed by Martinsson and Nilsson [129], similar to that used to determine total residual saponifiables in neutral oils. Neutrals, including alkanes, alkenes, secondary alcohols, and sultones, as well as the sulfonate esters in the AOS, are isolated by extraction from an aqueous alcoholic solution with petroleum ether. The sulfonate esters are separated from the sultones by chromatography on a silica gel column. Each eluent fraction is subjected to saponification and measured as active matter by MBAS determination measuring the extinction of the trichloromethane solution at 642 nra. (a) Sultones. Connor et al. [130] first reported, in 1975, a very small amount of skin sensitizer, l-unsaturated-l,3-sultone, and 2-chloroalkane-l,3-sultone in the anionic surfactant produced by the sulfation of ethoxylated fatty alcohol. These compounds can also be found in some AOS products consequently, methods of detection are essential. 

When the sulfenate ROSR is one where R SO- is the anion of a particularly acidic sulfenic acid and R+ is an easily formed carbonium ion, then isomerization to the sulfoxide by a mechanism involving an [R+ OSR l ion pair intermediate becomes possible. Braverman and Svendi (1974) found that on being heated in hexane solution / -methoxybenzyl trichloromethane-sulfenate [25] isomerized rather readily to the corresponding sulfoxide (93). 

The trichloromethyl carbanion, CC13-, which is formed by the deprotonation of trichloromethane, CHCI3, may, under favourable conditions, lose a chloride anion. Write down the balanced equation... 

Scheme 7.25. A pathway for the production of dichlorocarbene by treatment of trichloromethane (chloroform [HCCfi]) with aqueous base. The first step is rapid and reversible and produces carbanion, which, in the rate-determining step, loses chloride anion (Cl ) (See, Wagner, W. J. Proc. Chem. Soc., 1959,229 ).

Scheme 9.90. One possible pathway (involving nucleophilic displacement of chloride anion by phenoxide anion at a position ortho- or para- to the original hydroxyl [-OH] group) for the Reimer-Tiemann conversion of a phenol to a mixture of phenolic aldehydes. The hydroxy-benzene (phenol) is treated with trichloromethane (chloroform, CHCI3) and aqueous sodium hydroxide (NaOH(aq)).

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