Preparation of 2,3-Dichloropyridine by Selective Dechlorination of 2,3,6-Trichloropyridine

摘要

Activated carbon supported palladium catalyst was prepared by excessive impregnation method.The performance of catalyst was evaluat-ed by selective dechlorination of 2.3.6-richlopridine to 23-dichloropyridine.The inluence of palladium loading.reaction temperature and acid-binding agent on the eatalyst activity was invetigated.Resuls showed that the palladium load of 0.5%6(w),under the condition of the reaction temperature 140℃,the cornverion of 2.3.6 trichloropyridine was 100%and the sletivrity of 2.3-dichlropridine was more than 71%.Adding ti-ethylamine in solvent methanol can efectively improve the target product selectivity,and under the optimal conditions,the Belectivity of 23-dichlopyridine can reach to 80%.