6-氯咪唑并[1,2-b]哒嗪氢解脱卤反应动力学研究

采用Pd/C催化剂在排除扩散影响的条件下,研究了常压下6-氯咪唑并1,2-b]哒嗪氢解脱卤合成咪唑并1,2-b]哒嗪的反应动力学,通过空白试验消除催化剂及溶剂对吸氢量的影响,以吸氢量来表征反应程度。试验测定了反应温度、pH值对反应速率的影响。研究结果表明,在试验条件下,6-氯咪唑并1,2-b]哒嗪氢解脱卤反应对6-氯咪唑并1,2-b]哒嗪表现为零级,反应表观活化能为44.8kJ/mol,指前因子为7.68×104mol.L-1.min-1。pH值为8时有利于反应进行。

Kinetics of Hydrogenolysis Dehalogen of 6-Chloro-imidazo [ 1,2-b ] pyridazin

The reaction kinetics of synthesis of imidazopyridazine by hydrogenolysis of 6-chloro-imidazopyridazine was studied over Pd/C catalyst in an atmosphere of hydrogen.Both internal and external diffusions' effects were eliminated by stirring adequately.The effects of catalyst and solvent were eliminated by the experiments without adding substrate.The changes of the absorption amount of hydrogen with reaction time were measured to monitor the reaction extent.Results showed that the reaction was the zero-order with respect to 6-chloro-imidazo pyridazine under the experimental conditions.The apparent activation energy(Ea) of the reaction is 44.8 kJ/mol,and the pre-exponential factor(A) is 7.68×104 mol·L-1·min-1.The reaction underwent easily when the pH value is 8.