These include indoles, flavones, benzoflavones, imidazoles and pyridines. This reaction is a practical route to some substituted pyridines. It belongs to the reactive groups of&colon; amines, phosphines and pyridines. The Reissert reaction is also successful with isoquinolines and most pyridines. The biodegradation of pyridines proceeds via multiple pathways. Variant of this reaction are exploited for the synthesis of substituted pyridines. The nitrogen compounds include pyridines, picolines and pyrazines. Many related cations are known involving substituted pyridines, e.g. picolines, lutidines, collidines. Lewis bases such as tertiary amines and pyridines increase the rate of dihydroxylation. He also developed the Hammick reaction which generates ortho-substituted pyridines. In fact, heating NH3 and glycoaldehyde spontaneously forms a variety of pyridines, including pyridoxal. It is often used to dry basic solvents, especially amines and pyridines. The bis-triazinyl pyridines are related to terpyridine in their binding to metals. The methylthio and amino pyridines were found to be formed in the same ratio. The most odorous chemicals in cigar smoke are pyridines.