Journal of Molecular Catalysis A-Chemical, Vol.172, No.1-2, 165-173, 2001
Reaction of N-alkyl-2-benzothiazolesulphenamide with acetic anhydride in the presence of acids I. Technological aspects
The reaction of N-alkyl-2-benzothiazolesulphenamide with acetic anhydride in a non-polar solvent and in the presence of carboxylic or mineral acids at temperatures of 50-90 degreesC has been studied. At low initial concentration of an acid or in its absence a typical autocatalytic behavior of the reaction is observed. However, at higher concentration of acetic acid (>3 mol dm(-3)), phosphoric or sulphuric acid (>0.2 mol dm(-3)) the autocatalytic course of the reaction disappeared and higher rate of an N-alkyl-2-benzothiazolesulphenamide conversion was observed. The molar ratio of formation of the desired product, alkylbis(2-benzothiazolylsulphen)amide, to the main by-product, alkylamide of acetic acid, is up to 1.6 in the acid catalyzed reaction. The type of alkyl derivatives of 2-benzothiazolesulphenamide has a strong effect on the rate of formation of the corresponding alkylbis (2-benzothiazolylsulphen) amide. The yield of alkylbis(2-benzothiazolylsulphen) amides varies between 80-20 mol% at total conversion of the corresponding sulphenamides in the following order: IPbisBS > CHbisBS > TBbisBS > TAbisBS.
Keywords:N-alkyl-2-benzothiazolesulphenamides;alkylbis(2-benzothiazolylsulphen)amide;acetic anhydride;acid catalysis