About the synthesis process of pyridine

Pyridine can be obtained from natural coal tar or from acetaldehyde and ammonia. Pyridine and its derivatives can also be synthesized by a variety of methods, the most widely used of which is the synthesis of Hanchipyridine, which uses two molecules of β-carbonyl compounds, such as ethyl acetoacetate, to condense with one molecule of acetaldehyde. Condensation with a molecule of ethyl acetoacetate and ammonia to form a dihydropyridine compound, followed by dehydrogenation with an oxidizing agent such as nitrous acid, followed by hydrolysis of the decarboxylated pyridine derivative. It can also be prepared by passing a catalyst at 500 ° C with acetylene, ammonia and methanol.