The kinetic study of N-alkylation of imidazole with n-butyl bromide in the presence of phase transfer catalysts has been investigated. The reaction rates determined either by chemical analysis or by ^1H NMR technique are linearly dependent on concentration of n-butyl bromide and the catalyst. The rate constant(k) of the reaction of imidazole and n-butyl bromide with tetrabutylammonium bromide (1 mol%) as phase transfer catalyst at temperature 60 +/- 0,05`C is (1.90 +/- 0.02) X 10^-^2 min^-^1 and its activation energy (Ea) is 11.7 +/- 0.5 kcal/mol. An ion pair mechanism and a reaction course are proposed and discussed.

Key words: REACTION KINETICS, IMIDAZOLE, ALKYLATION, PHASE TRANSFER CATALYSIS