An environmentally benign method to accelerate the pinacol rearrangement in high temperature liquid water by the addition of CO2 was proposed.The effects of CO2 initial pressure and temperature on the kinetics of pinacol rearrangement were studied.The experimental results showed that the reaction rate could be greatly increased with the addition of CO2.The activation energies evaluated were 81.1 kJ·mol-1 without CO2,and 87.1 kJ·mol-1 with CO2 initial pressure at 0.2 MPa,which showed no significant difference.The main by-product was confirmed to be 2,3-dimethyl-3-butadiene by GC/MS and the possible reaction mechanism was proposed.
Adenine is an important chemical material widely used in the fields of medicine,organic synthesis and so on.Presently,adenine is produced from the condensation of diethyl malonate with formamide,which has serious pollution problems.To achieve the green production of adenine,non-catalyzed hydrolysis of adenosine in high temperature liquid water was carried out.The effects of initial concentration,agitating speed and temperature on adenosine hydrolysis were studied and the kinetics of adenosine hydrolysis was investigated at temperatures from 150℃ to 190℃.Rate constants were evaluated with the zeroth-order reaction assumption and the activation energy was 134.1 kJ·mol-1.The experimental results demonstrated that high selective preparation of adenine by non-catalyzed hydrolysis of adenosine in high temperature liquid water was possible.
