Arylsulphonyl chlorides

The preparation of arylsulphonamides from arylsulphonyl chlorides (Expts 6.42 to 6.45). 

The preparation of arylsulphonate esters from arylsulphonyl chlorides (Expt 6.46). 

The arylsulphonyl chlorides may be obtained more conveniently from the aromatic hydrocarbon by reaction with an excess of chlorosulphonic acid (chlorosulphonation)... 

Arylsulphonyl chlorides may be readily converted into the corresponding arylsulphonamides (e.g. by treatment with solid ammonium carbonate or with concentrated ammonia solution) or into a substituted arylsulphonamide (by reaction with the appropriate amino compound). Arylsulphonylhydrazides (for use in the preparation of aliphatic nitriles, Section 5.13.2, p. 712) may be prepared by a similar reaction using anhydrous hydrazine.20... 

These are prepared by the interaction of the arylsulphonyl chloride and an alcohol or phenol in the presence of sodium hydroxide solution or of pyridine (Expt 6.46). 

Reduction of an arylsulphonyl chloride with zinc dust and water affords the zinc salt of the sulphinic acid, converted by sodium carbonate to the sodium salt, in which form it is conveniently isolated (e.g. sodium toluene-p-sulphinate, Expt 6.47) and thence by hydrochloric acid into the somewhat unstable sulphinic acid. 

More vigorous reduction of arylsulphonyl chlorides (or of sulphinic acids), for example with zinc and dilute sulphuric add, gives rise to thiophenols, which are conveniently isolated by steam distillation. 

Selective acylation was also possible with four equivalents of an arylsulphonyl chloride or an aroyl chloride furnishing 76c " and 76d, in yields up to about 50%, while the regioselective acylation fails with aliphatic acid chlorides. Reaction with benzyloxycarbonyl chloride (EtsN, MeCN, RT), however, allowed the partial protection of four hydroxy groups to yield 76e. Compounds 76c-76e (interesting as building blocks for various self-assembled structures ) may be used for further derivatizations. 

The use of arylsulphonyl chlorides in place of DCC in the synthesis of phosphatidyl cholines gives products with a higher molar rotation than has been obtained previously, ... 

Polysulphonylation - The second important route to poly-arylsulphones is a polysulphonylation process in which sulphone linkages are formed by reaction of arylsulphonyl chlorides with aromatic nuclei (4). 

Arylsulphonyl chlorides 160 after conversion into acyl chlorides 167... 

Similarly to acyl chlorides, arylsulphonyl chlorides react with primary and secondary amines. A number of arylsulphonyl chlorides have also been investigated by Clark and Wells [9]. The reaction and the conditions of derivatiz-ation used were similar to those for acyl chlorides. The spectrophotometric properties of some typical benzene-sulphonamides are given in Table 2. 

Trichloroethanol has been used as a protecting group in the triester approach for the synthesis of deoxyribo- [29] as well as ribo-oligonucleotides [30]. It can be removed selectively by reduction with Zn or Zn/Cu, as previously discussed. The triesters may be synthesized either by stepwise addition of the two properly protected nucleosides to, , -trichloroethyl phos-phorodichloridate (Fig. 6.11a) or by condensation of a/3, 3, 3-tri-chloroethyl ester of a nucleotide with a nucleoside using an arylsulphonyl chloride as a condensing agent (Fig. 6.11b). 

Dissolve 1 g of the substance in 5 ml of chloroform previously dried with calcium chloride, cool the solution in an ice-bath, and when at 0°, add drops of chlorosulphonic add very carefully. When 3 ml of the add have been added in this way (keeping the mixture at 0°) and evolution of hydrogen chloride has ceased, allow the temperature to rise. Stir for about 30 minutes, and then pour, very slowly and with the greatest care, on to about 25 g of crushed ice. Protect the eyes during the last operation as spattering often occurs. Separate the chloroform layer, wash it wifli water, dry with anhydrous calcium chloride, and remove the solvent. If a solid, the crude arylsulphonyl chloride may be recrystallized from chloroform. It is then converted into the amide by heating 0 5 g of it with 5 ml of O 880 ammonia for 10 minutes. Cool and add 10 ml of water. Filter, wash the solid with water and recrystallize it from aqueous alcohol. 

Polymerization reactions involving the use of mixed anhydrides, formed in situ, have been reported to give fairly high molecular weight polymers, as for example in the recent report of the use of arylsulphonyl chlorides to effect the direct polycondensation of aromatic dicarboxylic... 

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