15867-75-1Relevant academic research and scientific papers
Effects of CH3OH-H2O and CH3OH Solvents on Rate of Reaction of Phthalimide with Piperidine
Khan, M. Niyaz
, p. 29 - 40 (2001)
Pseudo-first-order rate constants (κobs) for the cleavage of phthalimide in the presence of piperidine (Pip) vary linearly with the total concentration of Pip ([Pip]-) at a constant content of methanol in mixed aqueous solvents containing 2 percent v/v acetonitrile. Such linear variation of κobs against [Pip]t exists within the methanol content range 10 percent - 80 percent v/v. The change in κobs with the change in [Pip]t at 98 percent v/v CH3OH in mixed methanol-acetonitrile solvent shows the relationship: κobs = Sknapp[Pip]t + kgbapp[Pip]t2, where respective Sknapp and kgbapp represent apparent second-order and third-order rate constants for nucleophilic and general base-catalyzed piperidinolysis of phthalimide. The values of κobs obtained within [Pip]t range 0.02-0.40 M at 0.03 M NaOH and 20 as well as 50 percent v/v CH3OH reveal the relationship: κobs = κ0/(1+[κn(Pip)]/κox[-OX]t), where κ0 is the pseudo-first-order rate constant for hydrolysis of phthalimide, κn and κox represent nucleophilic second-order rate constants for the reaction of Pip with phthalimide and for the XO--catalyzed cyclization of N-piperidinylphthalamide to phthalimide, respectively, and [-OX]t) = [NaOH] + [-OXre], where [-OXre] = [-OHre] + [CH3Ore-]. The reversible reactions of Pip with H2O and CH3OH produce -OHre and CH3Ore- ions. The effects of mixed methanol-water solvents on the rates of piperidinolysis of PTH reveal a nonlinear decrease in κnapp with the increase in the content of methanol.
Effect of CH3CN-H2O and CH3CN solvents on rate of reaction of phthalimide with piperidine
Khan, M. Niyaz
, p. 187 - 193 (2007/10/03)
Pseudo-first-order rate constants (kobs) for the reaction of piperidine with phthalimide vary linearly with the total concentration of piperidine ([Pip]T) at a constant content of CH3CN in H2O-CH3CN solvents within the CH3CN content range 2-80 % (v/v). The change in kobs with the change in [Pip]T at 100% (v/v) CH3CN obeys the relationship kobs = Ψ [Pip]T2/(1 + Φ [Pip]T). Copyright John Wiley & Sons, Ltd.
