Kinetics and mechanism of hydroxy compound cinnamoylation in acetonitrile catalyzed by N-methylimidazole and 4-dimethylaminopyridine.
The kinetics of reaction of the acylating agents trans-cinnamic anhydride and trans-cinnamoyl chloride with the hydroxy compounds n-propyl alcohol and water in the presence of N-methylimidazole and 4-dimethylaminopyridine were studied spectrophotometrically in acetonitrile solution at 25 degrees. The acid chloride reacted via the intermediate formation of the N-acyl catalyst, which underwent general base-catalyzed reaction with the hydroxy compound. The anhydride did not form the N-acyl intermediate, but instead underwent direct general base catalysis. In the presence of water, all systems formed the N-acyl intermediate. The mechanistic route followed by the system was determined by the nucleophilicity of the catalyst, the ability of the leaving group, and the polarity of the solvent.
D000433:1-Propanol; D015761:4-Aminopyridine / Q000031:analogs & derivatives*; D000097:Acetonitriles; D000215:Acylation; D000631:Aminopyridines; D002934:Cinnamates; D007093:Imidazoles; D007700:Kinetics
D000097:Acetonitriles; D000631:Aminopyridines; D002934:Cinnamates; D007093:Imidazoles; C037551:cinnamoyl chloride; C031613:cinnamic anhydride; D000433:1-Propanol; D015761:4-Aminopyridine; C018100:1-methylimidazole; C003885:4-dimethylaminopyridine