Silica supported potassium oxide catalyst for dehydration of 2-picolinamide to form 2-cyanopyridine

The dehydration of 2-picolinamide to produce 2-cyanopyridine was investigated thoroughly using silica supported potassium oxide as a heterogeneous catalyst. Both large specific surface area and pore size of SiO2(B) contributed to the favorable catalytic performance for the synthesis of 2-CP. In addition, the yield of 2-CP showed the linear relationship with the amounts of medium basicity of the catalysts, demonstrating that medium basic sites were the active sites of silica supported potassium oxide catalysts. The catalysts were further characterized by XRD and FT-IR to clarify the active species. The results indicated the Si-O-K group produced by the reaction of K2CO3 with Si-OH was the active species, which was further evidenced by the adjustment of the amount of Si-OH by silylation and hydroxylation procedure. (C) 2018 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.