Catalytic Synthesis of Pyridine Bases in the Vapor Phase. XII
Abstract
A process for synthesizing 2, 3-cycloalkenopyridine by catalytic vapor-phase reaction from allyl alcohol, alicyclic ketone, and ammonia was found. The use of cyclopentanone, cyclohexanone, and cycloheptanone as the alicyclic ketones gives the corresponding cyclopenteno- (II), cyclohexeno- (I), and cyclohepteno-pyridines (III) in a good yield. As by-products of this reaction, 3-picoline and a minute amount of 3, 5-lutidine are formed, while quinoline (IV) is formed in a small amount in the case of (I). Since quinoline can be obtained by dehydrogenation of 2, 3-cyclohexeno-pyridine (I), the effect of activity of various catalysts and their concentration, reaction temperature, molar ratio of starting materials, and flow rate on the yield were examined from the point of industrial manufacture.