Direct Vapor-phase Alkylation of Pyridines with Alcohols over Nickel Substituted Zeolites

Abstract

Direct vapor-phase methylation of pyridine with methanol has been studied with various supported nickel oxide, catalysts. A nickel substituted Y type zeolite (NiY) catalyst was found to have the highest catalytic activity. The catalytic activity of the NiY catalyst appeared at 250°C, and reached a maximum at 350°C. At 350°C, we obtained 78% in the conversion of pyridine, and 77% and 23% in the selectivities to alpha-picoline and to 2, 6-lutidine, respectively. The selectivity to 2, 6-lutidine was found to increase with the increase of reaction temperature and methanol pressure and with the decrease of the flow rate of carrier gases.
It was also found that the methylation of α-picoline, β-picoline, and γ-picoline with methanol, ethylation of pyridine and picolines with ethanol, and methylation of 2, 4-lutidine with methanol took place over the NiY catalyst and that high yields were obtained for the formation of α-alkylated derivatives.