5-(Trifluoromethyl)-2-pyridone (CAS number 33252-63-0) is a trifluoromethyl substituted 2-pyridone. The tautomer of 5-(trifluoromethyl)-2-pyridone is 5-(trifluoromethyl)-2-hydroxypyridine in which its hydrogen locates on the oxygen. Fourier-transfer infrared (FT-IR) spectroscopy shows that in solid state 2-pyridone C=O stretching frequency is present while the O-H stretching is absent, indicating the hydrogen is closer to the nitrogen than the oxygen. 5-(Trifluoromethyl)-2-pyridone is heavily exploited in catalytic reactions, especially in palladium catalyzed directives and non-directive sp3/sp2 carbon-hydrogen activations. During the catalytic cycle, 5-(trifluoromethyl)-2-pyridone elongates the C-H bond with hydrogen bonding forming a 6-membered palladacycle intermediate.
5-(Trifluoromethyl)-2-pyridone serves as a hydrogen bond acceptor (ketone) and donor (amine), as well as a bioisostere for amides, benzenes, and pyridines, which is ideal for drug discovery. The trifluoromethyl group increases the lipophilicity of 5-(trifluoromethyl)-2-pyridone improving the permeability to the cell membranes.