Pyridine, C5H5N, is a colorless heterocyclic aromatic
base with an unpleasant smell, found in bone
oil and coal tar. It is produced from acetaldehyde (ethanal) and ammonia. Pyridine is used
as a solvent and to denature grain alcohol
(ethanol). Important derivatives are pyridoxine and niacin (see vitamin
|(A) Pyridine (azine), and (B) pyridoxine, one of
three naturally-occurring forms of vitamin B6.