Electrophilic additions to alkenes. Part IV. Kinetics of the reaction of 2,4-dinitrobenzenesulphenyl bromide with cyclohexene in benzene and in chloroform solution

Abstract

The kinetics of the reaction between 2,4-dinitrobenzenesulphenyl bromide and cyclohexene have been studied in benzene and in chloroform. In the latter the reaction is of the second order, first-order in each reactant, but in the former the order is greater than unity in sulphenyl bromide and the reaction is accelerated by the product. The rate equation proposed for benzene solution is: Rate =k₂⁰[B][ArSBr]+k₃[B][ArSBr]²+k₅[B][ArSBr][P], where B = cyclohexene and P = product. These results are compared with previous ones for the addition of 2,4-dinitrobenzenesulphenyl halides to cyclohexene in various solvents, and the velocity constants correlated with E_T-values for solvent polarity. The mechanism and kinetics of these reactions are discussed.