THE FLUORINATION OF 2,4,5-TRICHLORO-6-METHYLPYRIMIDINE; EXPERIMENTAL STUDY AND CNDO/2 CALCULATION

Article abstract of DOI:10.1016/S0022-1139(00)85019-8

A study of the kinetics and mechanism of the fluorination of 2,4,5-trichloro-6-methylpyriimidie (TCMP) to form 2,4-difluoro-5-chloro-6-methylpyrimidine (DFCMP) in polar aprotic solvents with KF or NaF has been performed.The rate constants of the fluorination under various conditions were measured.This fluorination proceeds as a pseudo-first-order consecutive reaction.The values of the activation enthalpy ΔH^*, the activation entropy ΔS^* and Arrhenius activation energy ΔEa were evaluated and the influence of solvents, catalysts and fluorinating agents was discussed.The CNDO/2 method has been applied to the calculation of the reaction path of the fluorination and the energy levels of the components.The calculated results agree well with experimental observation.