Group 17 halides reaction with

Sulfonic esters are most frequently prepared by treatment of the corresponding halides with alcohols in the presence of a base. The method is much used for the conversion of alcohols to tosylates, brosylates, and similar sulfonic esters. Both R and R may be alkyl or aryl. The base is often pyridine, which functions as a nucleophilic catalyst, as in the similar alcoholysis of carboxylic acyl halides (10-21). Primary alcohols react the most rapidly, and it is often possible to sulfonate selectively a primary OH group in a molecule that also contains secondary or tertiary OH groups. The reaction with sulfonamides has been much less frequently used and is limited to N,N-disubstituted sulfonamides that is, R" may not be hydrogen. However, within these limits it is a useful reaction. The nucleophile in this case is actually R 0 . However, R" may be hydrogen (as well as alkyl) if the nucleophile is a phenol, so that the product is RS020Ar. Acidic catalysts are used in this case. Sulfonic acids have been converted directly to sulfonates by treatment with triethyl or trimethyl orthoformate HC(OR)3, without catalyst or solvent and with a trialkyl phosphite P(OR)3. ... 

This is a synthetically useful procedure because the a-halo acids are useful starting materials for other reactions. For example, the addition of hydroxide ion leads to the replacement of the halogen with an -OH group. The reaction with ammonia replaces the halogen with -NH2. The reaction with cyanide ion, CN , converts the halide to a nitrile. Figure 12-33 illustrates this reaction. 

ZEREVITINOV DETERMINATION. A method of analysis of organic compounds containing active hydrogen atoms, as in hydroxy, carboxy, or unino groups, by reaction with methyl magnesium halide to yield methane quantitatively ROH + CH3MgX---------CH4 + ROMgX. 

B sulfonyl chloride is an amine-reactive reagent made by converting the 5-sulfonate group over to the reactive sulfonyl halide. Reaction with proteins and other amine-containing molecules results in the formation of sulfonamide bonds (Fig. 214). Lis-samine is a trademark erf Imperial Chemical Industries. 

The halogen in the acylglycosyl halide is reactive and may be readily displaced, for example, by an alkoxy group on reaction with an alcohol under anhydrous conditions in the presence of a silver or mercury(n) salt. In this case the products are glycosides which are the mixed cyclic acetals related to the cyclic hemiacetal forms of the monosaccharides. In the case of the D-glucose derivative shown below (and of other 1,2-cis acylglycosyl halides) the replace-... 

A-Alkylthiabenzenes are deprotonated by LDA and subsequent reaction of the anion with alkyl halides and ketones results in functionalization of the A-methyl group. However, reaction with esters leads to products arising from migration of the acylated methyl group (Scheme 108) <2000MI22>. 

Tellurium bis[dithiocarboxylates] lose one dithiocarboxylate group in reactions with equimolar amounts of chlorine, bromine, iodine, (V-chlorosuccinimide, or N-bromosuccinimide. The products, tellurium dithiocarboxylate halides, precipitate from the reaction mixtures . 

Two activating electron-withdrawing groups are better than one and dinitration of chlorobenzene makes a very electrophilic aryl halide. Reaction with hydrazine gives a useful reagent. 

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