Effect of CH3CN-H2O and CH3CN solvents on rate of reaction of phthalimide with piperidine

Abstract

Pseudo-first-order rate constants (k obs ) for the reaction of piperidine with phthalimide vary linearly with the total concentration of piperidine ([Pip] T ) at a constant content of CH 3 CN in H 2 O-CH 3 CN solvents within the CH 3 CN content range 2-80 % (v/v). The change in k obs with the change in [Pip] T at 100% (v/v) CH 3 CN obeys the relationship k obs = É [Pip] T 2 /(1 Φ [Pip] T ).A obs app X 0 expÀk obs t A I 1 using a non-linear least-squares technique considering app (apparent molar absorptivity) and A ? (the absorbance at reaction time t = ?) as unknown parameters. In Eqn. 1, A obs is the absorbance at any reaction time, t, and [X] 0 is the initial concentration of phthalimide (PTH), i.e. the concentration of PTH at t = 0, app = PTH À P (where PTH and P represent the molar absorptivities of PTH and JOURNAL OF PHYSICAL ORGANIC CHEMISTRY