2-(9H-Fluoren-9-yl)-4-(4-fluoro­anilino)-4-oxo­butanoic acid

In the title compound, C₂₃H₁₈FNO₃, the tricyclic 9-fluorenyl system is approximately planar (r.m.s. deviation = 0.0279 Å). The N—C(=O) bond length is comparatively short [1.359 (3) Å], which is typical for such conjugated systems. The N atom has a planar configuration [sum of bond angles= 359.8°] due to conjugation of its lone pair with the π-system of the carbonyl group. In the crystal, a three-dimensional network is formed through N—H...O and O—H...O hydrogen bonds between the amide and carb­oxy­lic acid groups and carbonyl O-atom acceptors.