P-Toluenesulfonyl

If the temperature is not kept below 25°C dunng the reaction of primary alcohols with p toluenesulfonyl chloride in pyndine it is sometimes observed that the isolated product is not the desired alkyl p toluenesulfonate but is instead the corresponding alkyl chlonde Suggest a mech anistic explanation for this observation... 

Conversion to p toluenesulfonate es ters (Section 8 14) Alcohols react with p toluenesulfonyl chloride to give p toluenesulfonate esters Sulfo nate esters are reactive substrates for nucleophilic substitution and elimma tion reactions The p toluenesulfo nate group is often abbreviated —OTs... 

The reaction of alcohols with acyl chlorides is analogous to their reaction with p toluenesulfonyl chloride described earlier (Section 8 14 and Table 15 2) In those reactions a p toluene sulfonate ester was formed by displacement of chloride from the sulfonyl group by the oxygen of the alcohol Carboxylic esters arise by displacement of chlonde from a carbonyl group by the alcohol oxygen... 

As in dry compounding, acid acceptors must be incorporated into neoprene latices because of the wide use of these latices in coating fabrics and metals. The hydrochloric acid that forms during service life has a particularly destmetive effect on coated cotton fabrics that are not adequately protected. High zinc oxide concentration (ca 15 parts) and use of 0.4 parts AJ-phenyl-AT(p-toluenesulfonyl)-/)-phenylenediamine (Aranox, Uniroyal) as an antioxidant provides adequate protection. 

Antioxidants resistant to extraction by lubricants and gasoline are preferred for the stabili2ation of elastomers used in automotive appfications such as gaskets and tubing. Aromatic amine antioxidants, such as A/-phenyl-Ar-(p-toluenesulfonyl)-A-phenylenediamine [100-93-6] (37), with low solubifity in hydrocarbons, are extracted slowly from elastomers and are used for these appfications. 

A novel method for preparing amino heterocycles is illustrated by the preparation of 2-amino-5-methylthiophene (159). In this approach vinyl azides act as NH2 equivalents in reaction with aromatic or heteroaromatic lithium derivatives (82TL699). A further variant for the preparation of amino heterocycles is by azide reduction the latter compounds are obtained by reaction of lithio derivatives with p- toluenesulfonyl azide and decomposition of the resulting lithium salt with tetrasodium pyrophosphate (Scheme 66) (82JOC3177). 

Imidazo[4,5-6]pyridine, 3-(2,3-0-isopropylidene-5-p-toluenesulfonyl-jS-D-ribofuranosyl)-intramolecular alkylation, 5, 616 Imidazo[4,5-6]pyridine, 1-methyl-bromination, 5, 617 nitration, 5, 617... 

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