Methylation of pyridine over zeolites

Methylation of pyridine was carried out on H-Y, Na-Y, HZSM-5, Mordenite, ZSM-22, SAPO-5, MgAlPO-11 and Zeolite Beta. The major products formed in the gas phase reaction were 2-picoline, 3-picoline and/or 4-picoline along with other alkylated products in certain cases. From the results it was envisaged that the 2-picoline and 4-picoline may be obtained by the Ladenburg rearrangement via N-alkylation whereas the 3-picoline may be obtained by an initial hydrogenation route. The selectivity for the various products varied from one catalyst to the other thereby proving the complexity of the reaction mechanism due to the size and shape effects of the pores in the zeolite matrix. © 1994, Elsevier Science B.V.