4Hydroxypyridine

4-Hydroxypyridine, also known as 4-pyridinol orpyridin-4-ol, is an organic compound with the chemical formula C5H5NO. It is a derivative of pyridine, where a hydroxyl group is attached to the fourth position of the pyridine ring. In its pure form, it is a white crystalline solid. 4-Hydroxypyridine exists in tautomeric equilibrium with its keto form, pyridin-4(1H)-one. This tautomerism is a significant characteristic of the molecule, influencing its chemical reactivity and physical properties.

The compound is soluble in water and polar organic solvents. Its chemical behavior is influenced by both the aromatic pyridine ring and the hydroxyl group. It can undergo reactions typical of phenols and amines, although the aromaticity of the ring modifies these reactions. 4-Hydroxypyridine serves as a building block in the synthesis of various more complex organic molecules, including pharmaceuticals and agrochemicals. It is also used as a ligand in coordination chemistry, forming complexes with metal ions. The study of 4-hydroxypyridine and its derivatives is an active area of research in organic and medicinal chemistry.