Mn. Khan et al., SOLVENT EFFECT ON INTRAMOLECULAR GENERAL BASE-CATALYZED AMINOLYSIS OFIONIZED PHENYL SALICYLATE, Indian journal of chemistry. Sect. B: organic chemistry, including medical chemistry, 33(8), 1994, pp. 752-757
The nucleophilic second-order rate constants (k1) for the reactions of
ionized phenyl salicylate (PS-) with primary and secondary amines in
70% (v/v) ethanol-water reveal Bronsted plots of slopes beta(nuc1) = 0
.32 +/- 0.10 and beta(nuc2) = 0.22 +/- 0.02, respectively. Different B
ronsted slopes obtained for the reactions of PS- with primary and seco
ndary amines suggest the occurrence of different locations of the tran
sition state in the critical rate-determining step. The change in wate
r content from 99.2 to 70% (v/v) in EtOH - H2O causes reduction in k1
by ca. < 3-fold for all the amines studied. Ionization constants of al
l the protonated amines turn out to be larger in 70% (v/v) EtOH - H2O
than in pure water.