Synthesis of n-butylcyanoacetate by ultrasonic waves. Kinetic comparison with thermal conditions

Fisher's esterification has been one of the most studied reactions in organic chemistry for esters production. This type of reaction commonly has the disadvantage of being very slow, thus, several alternative methods to accelerate them have been studied. In this work, the reaction between cyanoacetic acid and n-butanol catalyzed with p-toluensulfonic acid has been the objective. The effects of the reactants and the temperature on the reaction rate were studied under different thermal conditions. In addition, the effect of ultrasonic waves on the reaction was also considered. Compared to conventional heating method, the latter favored the reaction rate, being constant up to a certain temperature, after which the cavitation phenomenon does not occur, and the reaction slows down. Finally, using this methodology, no other products or collateral reactions were detected, meaning that the application of ultrasonic waves can be effective in increasing the industrial production of n-butylcyanoacetate.