ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 36, Number 3
JKCSEZ 36(3)
June 20, 1992 

The rates of hydrolysis of aryl phenylacetates have been measured in the presence of piperidine in 80% acetonitrile-20% water(v/v). For the electron withdrawing substituents of leaving group, the hydrolysis is catalyzed by a general base and the Hammett ρ_LG and Bronsted value β are 5.28 and -2.72 at 30℃, respectively. These high senstivities of Hammett and Bronsted values are E1cB mechanism. But in the electron donating ones, the hydrolysis is catalyzed by a specific base and B_AC2 mechanism is predominated. pK_SH's of phenylacetic acid ester and rate constants of hydrolysis k1, k-1, k2 were calculated.