TITLE:
Hydroxyalkylation of Cyclic Imides with Oxiranes Part III. Mechanism of the Reaction in Presence of Sodium Hydroxide Catalyst
AUTHORS:
Jacek Lubczak, Renata Lubczak, Dorota Naróg
KEYWORDS:
Imides, Oxiranes, Catalyst, Kinetic, Reactivity of Reagents, Thermodynamic Parameters, Mechanism of Reaction
JOURNAL NAME:
Open Journal of Physical Chemistry,
Vol.8 No.3,
August
30,
2018
ABSTRACT: The kinetics of reaction between cyclic monoimides (succinimide, phtalimide, and glutarimide) with ethylene and propylene oxides in presence of sodium hydroxide was studied.
The effect of substrate and catalyst concentrations on the course of the reaction was investigated. Kinetics of reaction was studied by dilatometry, i.e. by measuring volume
contraction of reaction mixture. The kinetic law describing the reaction of imides with oxiranes is: . where ccat, cAH and cB are concentrations of catalyst, imide, and oxirane, respectively. The relative reactivity of imides and oxiranes was: GI > PI ≥ SI and EO > PO. The reaction mechanism was proposed based upon experimentally determined rate law for the reaction of cyclic monoimides and oxiranes as well
as analytical and instrumental analysis of products. The elementary reaction between oxirane and imide anion is rate determining step. The imide anion is formed by hydrogen cation transfer into catalytic hydroxide anion from dissociated NaOH. In the consecutive elemental reaction an imidate anion attack on the oxirane molecule occurs. It is the slowest stage of the reaction, limiting the entire process. All the studied reactions obey the same mechanism as can be concluded
from isokinetic relationship of studied systems)