Pyridine/picoline production process

A process for shape selective base synthesis of pyridine or picoline compounds, comprising:

• (a) reacting a reactant feedstream comprising ammonia and at least one C.sub.1-5 carbonyl reactant under suitable synthesis reaction conditions of temperature, pressure, and space velocity in the presence of a catalyst comprising a molecular sieve to produce a primary product stream comprising pyridine or picoline products and polyalkylpyridines or higher molecular weight species;
• (b) separating from the primary product stream a product fraction comprising pyridine or picoline products, and a polyalkylpyridine fraction comprising polyalkylpyridines or other higher molecular weight aromatic species;
• and
• (c) recirculating the polyalkylpyridine fraction to the catalyst to convert polyalkylpyridines or other higher molecular weight aromatic species therein under the reaction conditions to produce a secondary product comprising pyridine or picoline products and less than about 5 wt % polyalkylpyridines or other higher molecular weight aromatic species.