MECHANISTIC STUDY OF THE ACID-CATALYZED FORMATION AND HYDROLYSIS OF MTBE IN NONPOLAR MEDIA

The acid catalyzed hydrolysis of MTBE using p-toluenesulfonic acid was studied in nonpolar medium to ascertain the effect of nucleophile upo n reaction. NMR measurements showed protonation of both MTBE acid meth anol by p-toluenesulfonic acid in nonpolar medium but no nucleophile-e lectrophile interaction of MTBE with p-toluenesulfonic acid methyl est er as potential nucleophile. Addition or in situ generation of a nucle ophile did not accelerate the reaction. At low conversions and low cat alyst concentration the reaction exhibited pseudo zero order with resp ect to reactant concentration and second order with respect to catalys t concentration. The results suggest protonation of MTBE in a fast pre equilibrium step in which the acid catalyst exhibits cooperative effec t. No nucleophilic assistance in the transition state of MTBE hydrolys is in nonpolar medium occurs.