Tosyl chloride, reaction

In general, the reaction can be performed between 0-60°C with the majority of the reactions being run at room temperature. The reactivity of the hydrazones with either the acyl or tosyl leaving group with thionyl chloride depends on the substrate. However, the acylated hydrazones generally provide gaseous by-products where as the tosyl chloride reaction products have to be separated from the reaction mixture. 

Now, let s draw out the forward scheme. This multi-step synthesis uses three equivalents of ethylene (labeled A, B, C in the scheme below) and one equivalent of acetic acid (labeled D). Ethylene (A) is converted to 1,2-dibromoethane upon treatment with bromine. Subsequent reaction with excess sodium amide produces an acetylide anion which is then treated with bromoethane [made tfom ethylene (B) and HBr] to produce 1-butyne. Deprotonation with sodium amide, followed by reaction with an epoxide [prepared by epoxidation of ethylene (C)] and water workup, produces a compound with an alkyne group and an alcohol group. Reduction of the alkyne to the cis alkene is accomplished with H2 and Lindlar s catalyst, after which the alcohol is converted to a tosylate with tosyl chloride. Reaction with the conjugate base of acetic acid [produced by treating acetic acid (D) with NaOH] allows for an Sn2 reaction, thus yielding the desired product, Z-hexenyl acetate. 

In the flask were placed 0.20 mol of the acetylenic alcohol, 0.24 mol of tosyl chloride and 350 ml of diethyl ether. The mixture was stirred at room temperature, until the solid had passed into solution and then cooled at -5 to -10 c in a bath of dry-ice and acetone. Machine-powdered KOH (130 g) was added with vigorous stirring, initially in relatively small portions [oa. 5 g), at intervals of 2 min. The reaction was strongly exothermic at first, and efficient cooling was necessary in order to maintain the temperature of the reaction mixture between -5 and O C... 

In the reaction with enamino ketones derived from dimedone (e.g., 49) p-toluenesulfonyl chloride gives the chloroiminium cation (138) isolated as the perchlorate. This indicates that initial O sulfonation is followed by addition of chloride ion and subsequent expulsion of tosylate (42) in a manner similar to the trichloroacetyl chloride reaction with 49 (Section IV.A). 

Tosylates are generally formed from an amine and tosyl chloride in an inert solvent such as CH2CI2 with an acid scavenger such as pyridine or triethyl-amine, They may also be prepared using the Schotten-Baumann reaction. 

It was recently shown that the formation of a Schiff s base is the first step of the reaction between 3-aminopropan-l-ol and an aldehyde. The action of acid chlorides, such as tosyl chloride, on the SchifTs base forms the W-acyl derivative of tetrahydro-1,3-oxazine. 

An analogous reaction occurs with dibenzoylacetylene, whereas the reaction fails with dimethyl acetylenedicarboxylate, benzoyl chloride and tosyl chloride. Decomplexation of compound 29 to 3-(cyclohepta-2,4,6-trienyl)-3//-azepine (73%) has been achieved with trimethylamine N-oxide. 

Dibenzo[l,3]diazepines 9, together with amidines and benzimidazoles, are produced by a rearrangement reaction when certain A.A -diarylamide oximes 7 are treated with tosyl chloride. The intermediate 0-tosyl derivatives 8 cannot be isolated.176... 

Sulfur compounds have also been widely studied as activating agents for polyesterification reactions. p-Toluenesulfonyl chloride (tosyl chloride) reacts with DMF in pyridine to form a Vilsmeir adduct which easily reacts with carboxylic acids at 100-120° C, giving highly reactive mixed carboxylic-sulfonic anhydrides.312 The reaction is efficient both for aromatic dicarboxylic acid-bisphenol312 and hydroxybenzoic acid314 polyesterifications (Scheme 2.31). The formation of phenyl tosylates as significant side products of this reaction has been reported.315... 

Note Several condensing agents for the direct poly condensation reaction such as diphenyl chlorophosphate-LiBr and tosyl chloride-DMF have also been developed by Higashi et al.311,312 (see Section 2.3.3.2). 

Recently Tanabe and co-workers have found that several alcohols were smoothly and efficiently tosylated using tosyl chloride/triethylamine and a catalytic amount of trimethylamine hydrochloride as reagents.6 Compared with the traditional method using pyridine as solvent, this procedure has the merit of much higher reaction rates, and it avoids the side reaction in which the desired tosylate is converted into the corresponding chloride. 

Fig. 3 Suggested mechanisms for the reaction of cellulose with tosyl chloride in the presence of pyridine (Py) and/or triethylamine (EtsN) base catalyst. Redrawn from [147]...

In order to activate the 1,2-diacylhydrazines towards cychzation, they were reacted with tosyl chloride (Scheme 8). While the reaction with tosyl chloride alone did not afford any of the desired product, and the cychzation in the presence of strong bases, although successful, posed the same problems of removal, excellent results were obtained in the presence of both tosyl chloride and a supported strong base, with polymer-bound BEMP giving better results than polymer-supported l,3,4,6,7,8-hexahydro-l-methyl-2H-... 

The Ley group also investigated the PS-base/tosyl chloride methodology developed by Brain (see above. Scheme 8) for the synthesis of 2-aminooxadiazoles from semicarbazides, especially with a view to directly synthesize 2-aminosulfonamide substituted 1,3,4-oxadiazoles, a compound class of interest for agrochemical and pharmaceutical apphcations (Scheme 10) [71]. In this case, the choice of the supported base was crucial for the result of the reaction weak bases (PS-DIEA, PS-NMM) could still afford the cyclized 2-aminooxadiazole product, but could not efficiently... 

Two of the hydroxyl groups present in each glucose unit of the cellulose are secondary, one is primary. Studies on the relative rates of etherification of the three hydroxyls are not conclusive. Mahoney and Purves,18 using a method which takes advantage of the rapid reaction between tosyl chloride and a primary hydroxyl, combined with a determination of unsubstituted glycol groups, have studied the relative num-... 

A rapid O-tosylation of a primary alcohol with tosyl chloride (1 equivalent) in the presence of 4-(N,N-dimethylamino)pyridine (1 equivalent) has been reported by Botta and coworkers (Scheme 6.118) [236], Microwave heating of the reaction mixture at 50 °C for 5 min provided the desired tosyl ester in 95% yield. 

The readily prepared support was then used for dihydropyrimidine and chalcone synthesis (Scheme 7.29). Thus, the modified support was activated prior to reaction by treatment with tosyl chloride. Solutions of the appropriate acetophenones were then spotted onto the membrane and the support was submitted to microwave irradiation for 10 min [45]. In the next step, several aryl aldehydes were attached under microwave irradiation to form a set of corresponding chalcones through a Claisen-Schmidt condensation. 

Free-radical chain reactions have been reviewed60. The cyclization of dienes by the action of free radicals is illustrated for the case of the 1,6-heptadiene derivative 90 (E = CC Me) in equation 56. Treatment with tosyl radicals, produced from tosyl chloride and a catalytic amount of dibenzoyl peroxide, generates the radicals 91, which cyclize to 92. The latter reacts with tosyl chloride to form 93 and tosyl radicals are regenerated. The product is obtained in 85% yield as a 6 1 mixture of cis- and fraws-isomers61. 

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