A Kinetics and Mechanism Investigation of the Nucleophilic Substitution Reaction of α‐Chlorododecyl Carboxylate with Trimethylamine

Abstract

A nucleophilic substitution reaction was developed to synthesize the zwitterionic surfactant using a renewable natural fatty acid rather than a petroleum derivative as the raw material. The kinetics and mechanism of the nucleophilic substitution reaction of trimethylamine a-chlorododecyl carboxylate with trimethylamine were investigated in protic and dipolar aprotic solvents including water, ethanol and N, N-dimethyl formamide. The rate equations were derived using initial rates and the activation parameters in different solvents were determined empirically and compared with each other to obtain important information about the reaction mechanism. The overall second-order reaction number and the negative activation entropy supported a bimolecular nucleophilic substitution (S N 2) mechanism, combined with the pseudo-first-order kinetics for each reactant. The experimental results also showed that the reaction reactivity diminishes with the decrease in polarity of protic solvents. The typical dipolar aprotic solvent dimethyl formamide distinctively promoted the reaction in. This fact was successfully explained by the solvation rule for S N 2 reactions.

Comparative studies on reaction of bis(p‐nitrophenyl) phosphate and α‐nucleophiles in cationic micellar media

“…Phosphodiesters are extremely stable compounds and are highly resistant toward hydrolytic cleavage at physiological pH. This high stability is in agreement with the fundamental role of DNA in the preservation of genetic information and underscores the importance of studies on the mechanism of phosphodiester hydrolysis . Many α‐nucleophiles such as hydroxylamine, hydrazine, hydroxamic acid, and oxime are truly effective dephosphorylating agents for phosphodiesters and triesters.…”

“…This high stability is in agreement with the fundamental role of DNA in the preservation of genetic information and underscores the importance of studies on the mechanism of phosphodiester hydrolysis. [5][6][7][8] Many a-nucleophiles such as hydroxylamine, [9] hydrazine, [10] hydroxamic acid, [4,11] and oxime [12] are truly effective dephosphorylating agents for phosphodiesters and triesters. There are unshared electron pairs on the atom adjacent to the nucleophilic center of these a-nucleophiles.…”